Japan Airlines Corp. has decided to pare its workforce by 13,000 by the end of March 2015 — or 4,000 more than planned — sources with knowledge of the new plan said Saturday.

The move would cut the payroll at Japan's largest airline and its group subsidiaries to around 35,000 and cut the subsidiaries to around 50 from roughly 120, the sources said.

JAL has decided to step up downsizing as the government mulls the use public funds to keep it afloat. The airline is expected to formulate the key points of the new turnaround plan by the end of the month.

The greater part of the job cuts will be at Japan Airlines International Co., the unit in charge of JAL's flights.

The extra 4,000 will come from selling part of JAL's stake in JAL Hotels Co., a unit that runs about 60 hotels at home and abroad, and from consolidating the overseas units of travel agency JALPAK Co.