A stimulus package worth more than ¥400 billion is being prepared to spur the economy as the recovery from the March 2011 earthquake and tsunami slows, government sources said.

The policy package, which will be the first in a series of emergency measures, originally started out at ¥200 billion but was doubled to revive the flagging economy. The Cabinet of Prime Minister Yoshihiko Noda is expected to approve it Friday.

The sources said the stimulus package will focus in part on supporting smaller businesses affected by the natural disasters and on promoting research on artificially derived multipurpose stem cells, a technology that won Kyoto University professor Shinya Yamanaka this year's Nobel Prize in physiology or medicine with British researcher John Gurdon.