American International Group Inc. has announced that Steven Udvar-Hazy will step down as chief executive and director of its aircraft leasing unit, International Lease Finance Corp.

Effective Friday, Udvar-Hazy retires as head of Century City-based ILFC as AIG figures out what to do with the unit. There has been speculation Udvar-Hazy could lead a group of investors in buying the unit from AIG.

ILFC President John Plueger will serve as acting CEO. Udvar-Hazy had previously relinquished his post as chairman.

AIG was one of the hardest hit financial firms during the credit crisis. It received an aid package worth more than $180 billion from the government. The insurer, based in New York, has been selling assets and streamlining operations to repay the government. ILFC has been one of AIG’s most valuable divisions.

Udvar-Hazy was succeeded as chairman of ILFC in December. That move, analysts said, eliminated a potential conflict of interest in his bid to buy back a portion of the aircraft leasing business that he co-founded and grew into one of the world’s largest.

Udvar-Hazy was succeeded as chairman by Douglas Steenland, former president and chief executive of Northwest Airlines. Steenland is on AIG’s board of directors. The succession fueled speculation that Udvar-Hazy would soon leave the company he co-founded in 1973, and start a rival business. He sold ILFC to insurance giant American International Group Inc. in 1990 but stayed on to manage it.