Washington is considering appointing U.S. Ambassador to Australia Thomas Shieffer as new ambassador to Japan to replace Howard Baker, sources said Friday.

Shieffer, 57, is known to have long been a close friend of U.S. President George W. Bush. He is considered to be unfamiliar with Japanese-U.S. relations but would help bilateral ties through his links with Bush, according to the sources.

Baker, 79, who has been ambassador to Tokyo since June 2001, underwent heart surgery this summer and was expected to leave office under a second Bush administration.

Texas-born Shieffer has been a business partner of Bush, with joint investments that include the major league baseball team Texas Rangers.