diff --git a/core/lib/Drupal/Component/Gettext/BatchStateInterface.php b/core/lib/Drupal/Component/Gettext/BatchStateInterface.php
new file mode 100644
index 0000000..df4e59e
--- /dev/null
+++ b/core/lib/Drupal/Component/Gettext/BatchStateInterface.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Drupal\Component\Gettext;
+
+/**
+ * Add state to an object to manage continue after a previous batch call.
+ *
+ * The class implementing this must make sure to pass all state.
+ * It's constructor must be empty as the batch interface needs to recreate
+ * it without constructor arguments.
+ *
+ *
+ * Example:
+ * <code>
+ * class MyReader implements BatchStateInterface {
+ *   function __construct(){
+ *     // empty
+ *   }
+ *   ...
+ *   function getState() {
+ *     return array(
+ *       'class' => __CLASS__,
+ *       'my_key' => 'my value',
+ *     );
+ *   }
+ * }
+ * </code>
+ */
+interface BatchStateInterface {
+
+  /**
+   * Returns the current state used for resetting state later on.
+   *
+   * The state is used to reconstruct the state of the object by calling
+   * setState().
+   *
+   * The Class implemeting this interface must have an empty constructor.
+   *
+   * @return array
+   *   key/value pairs of which one must be 'class' => __CLASS__
+   */
+  function getState();
+
+  /**
+   * Sets the object ready to roll.
+   *
+   * After calling setState it is assumed the object is ready to do it's work.
+   */
+  function setState(array $state);
+}
diff --git a/core/lib/Drupal/Component/Gettext/PoStreamReader.php b/core/lib/Drupal/Component/Gettext/PoStreamReader.php
index bd916a7..0e08667 100644
--- a/core/lib/Drupal/Component/Gettext/PoStreamReader.php
+++ b/core/lib/Drupal/Component/Gettext/PoStreamReader.php
@@ -9,6 +9,7 @@ namespace Drupal\Component\Gettext;
 
 use Drupal\Component\Gettext\PoReaderInterface;
 use Drupal\Component\Gettext\PoStreamInterface;
+use Drupal\Component\Gettext\BatchStateInterface;
 use Drupal\Component\Gettext\PoHeader;
 
 /**
@@ -17,7 +18,7 @@ use Drupal\Component\Gettext\PoHeader;
  * The PO file format parsing is implemented according to the documentation at
  * http://www.gnu.org/software/gettext/manual/gettext.html#PO-Files
  */
-class PoStreamReader implements PoStreamInterface, PoReaderInterface {
+class PoStreamReader implements PoStreamInterface, PoReaderInterface, BatchStateInterface {
 
   /**
    * Source line number of the stream being parsed.
@@ -205,6 +206,36 @@ class PoStreamReader implements PoStreamInterface, PoReaderInterface {
   }
 
   /**
+   * Implements Drupal\Component\Gettext\BatchStateInterface::setState().
+   */
+  public function setState(array $state) {
+    $this->setURI($state['uri']);
+    $this->setLangcode($state['langcode']);
+    // Make sure to (re)read the PoHeader
+    $this->open();
+    // Move to last read position.
+    if (isset($state['seekpos'])) {
+      fseek($this->_fd, $state['seekpos']);
+    }
+    if (isset($state['lineno'])) {
+      $this->lineno = $state['lineno'];
+    }
+  }
+
+  /**
+   * Implements Drupal\Component\Gettext\BatchStateInterface::getState().
+   */
+  public function getState() {
+    return array(
+      'class' => __CLASS__,
+      'uri' => $this->_uri,
+      'langcode' => $this->_langcode,
+      'seekpos' => ftell($this->_fd),
+      'lineno' => $this->lineno,
+    );
+  }
+
+  /**
    * Read the header from the PO stream.
    *
    * The header is a special case PoItem, using the empty string as source and
diff --git a/core/modules/locale/lib/Drupal/locale/Gettext.php b/core/modules/locale/lib/Drupal/locale/Gettext.php
index f3ba3b9..748f817 100644
--- a/core/modules/locale/lib/Drupal/locale/Gettext.php
+++ b/core/modules/locale/lib/Drupal/locale/Gettext.php
@@ -66,7 +66,7 @@ class Gettext {
    *
    * @see Drupal\locale\PoDatabaseWriter
    */
-  static function fileToDatabase($file, $langcode, $overwrite_options, $customized = LOCALE_NOT_CUSTOMIZED) {
+  static function fileToDatabase($file, $langcode, $overwrite_options, $customized = LOCALE_NOT_CUSTOMIZED, $seekpos = NULL, $items = -1) {
     // Instantiate and initialize the stream reader for this file.
     $reader = new PoStreamReader();
     $reader->setLangcode($langcode);
@@ -96,13 +96,25 @@ class Gettext {
 
     // Attempt to pipe all items from the file to the database.
     try {
-      $writer->writeItems($reader, -1);
+      if ($seekpos) {
+        $current_state = $reader->getState();
+        // Reset the lineno.
+        unset($current_state['lineno']);
+        $current_state['seekpos'] = $seekpos;
+        $reader->setState($current_state);
+      }
+      $writer->writeItems($reader, $items);
     }
     catch (Exception $exception) {
       throw $exception;
     }
 
     // Report back with an array of status information.
-    return $writer->getReport();
+    $report = $writer->getReport();
+
+    // Add the seek position to the report.
+    $current_state = $reader->getState();
+    $report['seekpos'] = $current_state['seekpos'];
+    return $report;
   }
 }
diff --git a/core/modules/locale/locale.bulk.inc b/core/modules/locale/locale.bulk.inc
index 8a9c2fe..1c83a27 100644
--- a/core/modules/locale/locale.bulk.inc
+++ b/core/modules/locale/locale.bulk.inc
@@ -108,45 +108,8 @@ function locale_translate_import_form_submit($form, &$form_state) {
       drupal_set_message(t('The language %language has been created.', array('%language' => t($language->name))));
     }
     $customized = $form_state['values']['customized'] ? LOCALE_CUSTOMIZED : LOCALE_NOT_CUSTOMIZED;
-
-    // Now import strings into the language
-    try {
-      // Try to allocate enough time to parse and import the data.
-      drupal_set_time_limit(240);
-
-      $report = GetText::fileToDatabase($file, $language->langcode, $form_state['values']['overwrite_options'], $customized);
-      $additions = $report['additions'];
-      $updates = $report['updates'];
-      $deletes = $report['deletes'];
-      $skips = $report['skips'];
-
-      menu_router_rebuild();
-      // Clear cache and force refresh of JavaScript translations.
-      _locale_invalidate_js($language->langcode);
-      cache()->deletePrefix('locale:');
-
-      drupal_set_message(t('The translation was successfully imported. There are %number newly created translated strings, %update strings were updated and %delete strings were removed.', array('%number' => $additions, '%update' => $updates, '%delete' => $deletes)));
-      watchdog('locale', 'Imported %file into %locale: %number new strings added, %update updated and %delete removed.', array('%file' => $file->filename, '%locale' => $language->langcode, '%number' => $additions, '%update' => $updates, '%delete' => $deletes));
-      if ($skips) {
-        if (module_exists('dblog')) {
-          $skip_message = format_plural($skips, 'A translation string was skipped because of disallowed or malformed HTML. <a href="@url">See the log</a> for details.', '@count translation strings were skipped because of disallowed or malformed HTML. <a href="@url">See the log</a> for details.', array('@url' => url('admin/reports/dblog')));
-        }
-        else {
-          $skip_message = format_plural($skips, 'A translation string was skipped because of disallowed or malformed HTML. See the log for details.', '@count translation strings were skipped because of disallowed or malformed HTML. See the log for details.');
-        }
-        drupal_set_message($skip_message, 'error');
-        watchdog('locale', '@count disallowed HTML string(s) in %file', array('@count' => $skips, '%file' => $file->uri), WATCHDOG_WARNING);
-      }
-      $variables = array('%filename' => $file->filename);
-      drupal_set_message(t('The translation import of %filename is done.', $variables));
-      watchdog('locale', 'The translation import of %filename is done.', $variables);
-
-    } catch (Exception $exc) {
-      drupal_set_message(print_r($exc, TRUE));
-      $variables = array('%filename' => $file->filename);
-      drupal_set_message(t('The translation import of %filename failed.', $variables), 'error');
-      watchdog('locale', 'The translation import of %filename failed.', $variables, WATCHDOG_ERROR);
-    }
+    $batch = locale_translate_batch_build(array($file->uri => $file), $form_state['values']['overwrite_options'], $customized, $form_state['values']['langcode'], TRUE);
+    batch_set($batch);
   }
   else {
     drupal_set_message(t('File to import not found.'), 'error');
@@ -285,10 +248,10 @@ function locale_translate_export_form_submit($form, &$form_state) {
 /**
  * Set a batch for newly added language.
  */
-function locale_translate_add_language_set_batch($langcode) {
+function locale_translate_add_language_set_batch($langcode, $overwrite_options = array(), $customized = LOCALE_NOT_CUSTOMIZED) {
   // See if we have language files to import for the newly added language,
   // collect and import them.
-  if ($batch = locale_translate_batch_import_files($langcode, TRUE)) {
+  if ($batch = locale_translate_batch_import_files($langcode, $overwrite_options, $customized, TRUE)) {
     batch_set($batch);
   }
 }
@@ -308,7 +271,7 @@ function locale_translate_add_language_set_batch($langcode) {
  *   l10n_update functionality to feed in translation files alike.
  *   See http://drupal.org/node/1191488.
  */
-function locale_translate_batch_import_files($langcode = NULL, $finish_feedback = FALSE, $force = FALSE) {
+function locale_translate_batch_import_files($langcode = NULL, $overwrite_options = array(), $customized = LOCALE_NOT_CUSTOMIZED, $finish_feedback = FALSE, $force = FALSE) {
   $files = array();
   if (!empty($langcode)) {
     $langcodes = array($langcode);
@@ -335,7 +298,7 @@ function locale_translate_batch_import_files($langcode = NULL, $finish_feedback
       }
     }
   }
-  return locale_translate_batch_build($files, $finish_feedback);
+  return locale_translate_batch_build($files, $overwrite_options, $customized, NULL, $finish_feedback);
 }
 
 /**
@@ -364,13 +327,13 @@ function locale_translate_get_interface_translation_files($langcode = NULL) {
  * @return
  *   A batch structure or FALSE if $files was empty.
  */
-function locale_translate_batch_build($files, $finish_feedback = FALSE) {
+function locale_translate_batch_build($files, $overwrite_options = array(), $customized = LOCALE_NOT_CUSTOMIZED, $langcode = NULL, $finish_feedback = FALSE) {
   $t = get_t();
   if (count($files)) {
     $operations = array();
     foreach ($files as $file) {
       // We call locale_translate_batch_import for every batch operation.
-      $operations[] = array('locale_translate_batch_import', array($file->uri));
+      $operations[] = array('locale_translate_batch_import', array($file->uri, $overwrite_options, $customized, $langcode));
     }
     $batch = array(
       'operations'    => $operations,
@@ -398,21 +361,47 @@ function locale_translate_batch_build($files, $finish_feedback = FALSE) {
  * @param $context
  *   Contains a list of files imported.
  */
-function locale_translate_batch_import($filepath, &$context) {
+function locale_translate_batch_import($filepath, $overwrite_options, $customized, $langcode = NULL, &$context) {
   // The filename is either {langcode}.po or {prefix}.{langcode}.po, so
   // we can extract the language code to use for the import from the end.
-  if (preg_match('!(/|\.)([^\./]+)\.po$!', $filepath, $langcode)) {
+  if ($langcode || preg_match('!(/|\.)([^\./]+)\.po$!', $filepath, $langcode)) {
     $file = entity_create('file', array('filename' => drupal_basename($filepath), 'uri' => $filepath));
-    // We need only the last match
-    $langcode = array_pop($langcode);
+    // We need only the last match.
+    if (is_array($langcode)) {
+      $langcode = array_pop($langcode);
+    }
     try {
-      $report = GetText::fileToDatabase($file, $langcode, array(), LOCALE_NOT_CUSTOMIZED);
-      $file->langcode = $langcode;
-      $file->timestamp = filemtime($file->uri);
-      locale_translate_update_file_history($file);
-      $context['results']['files'][$filepath] = $filepath;
-      $context['results']['stats'][$filepath] = $report;
-    } catch (Exception $exception) {
+      if (empty($context['sandbox'])) {
+        $context['sandbox']['parse_state'] = array(
+          'filesize' => filesize($file->uri),
+          'chunk_size' => 10,
+        );
+      }
+      $report = GetText::fileToDatabase($file, $langcode, $overwrite_options, $customized, $context['sandbox']['parse_state']['seekpos'], $context['sandbox']['parse_state']['chunk_size']);
+      // Not yet finished with reading, mark progress based on size and
+      // position.
+      // Maximize the progress bar at 95% before completion because batch API
+      // could trigger end of operation before file reading is done for floating
+      // point inaccuracies. See http://drupal.org/node/1089472
+      if ($report['seekpos'] < filesize($file->uri)) {
+        $context['sandbox']['parse_state']['seekpos'] = $report['seekpos'];
+        $context['finished'] = min(0.95, $report['seekpos'] / filesize($file->uri));
+        $context['message'] = t('Importing file: %filename (@percent%)', array('%filename' => $file->filename, '@percent' => (int) ($context['finished'] * 100)));
+      }
+      else {
+        // We are finished here.
+        $context['finished'] = 1;
+        $file->langcode = $langcode;
+        $file->timestamp = filemtime($file->uri);
+        locale_translate_update_file_history($file);
+        $context['results']['files'][$filepath] = $filepath;
+      }
+      // Add the values from the report to the stats for this file.
+      foreach ($report as $key => $value) {
+        $context['results']['stats'][$filepath][$key] += $report[$key];
+      }
+    }
+    catch (Exception $exception) {
       $context['results']['files'][$filepath] = $filepath;
       $context['results']['failed_files'][$filepath] = $filepath;
     }
@@ -448,6 +437,11 @@ function locale_translate_batch_finished($success, $results) {
       drupal_set_message($skip_message, 'error');
       watchdog('locale', '@count disallowed HTML string(s) in files: @files.', array('@count' => $skips, '@files' => implode(',', $skipped_files)), WATCHDOG_WARNING);
     }
+    menu_router_rebuild();
+
+    // Clear cache and force refresh of JavaScript translations.
+    _locale_invalidate_js();
+    cache()->deletePrefix('locale:');
   }
 }