NEW YORK (Reuters) - Hamid Biglari, a 12-year veteran of Citigroup (>> Citigroup Inc.) who was most recently head of emerging markets, is leaving the company, according to a memo from new CEO Mike Corbat on Monday.

Biglari, also a vice chairman and a member of the company's business development committee, will "explore other professional opportunities," according to the memo, which was seen by Reuters.

Biglari is the latest senior executive to leave as Corbat realigns the company's chain of command. In October, Corbat was suddenly named CEO to replace Vikram Pandit, whom the board pushed out.

Biglari, a former physicist and McKinsey consultant, joined Citigroup when Sanford "Sandy" Weill was its chief executive. He held senior positions at the bank, mainly at its investment bank, through multiple chief executives.

When Vikram Pandit was CEO, Biglari helped the bank figure out its post-crisis strategy. In October 2009, Biglari told the Wall Street Journal that Citigroup had to remake itself. He equated the bank's transformation to the switch that IBM (>> International Business Machines Corp.) made in the 1990's, when IBM Chief Executive Louis Gerstner focused less on areas like hardware and more on providing software and information technology services.

"People were writing IBM off then but Gerstner completely reinvented the company," Biglari said. "We, too, have to make the elephant dance," he added, referring to the title of Gerstner's 2003 memoir, "Who Says Elephants Can't Dance?"

(Reporting by David Henry in New York, additional reporting by Dan Wilchins; Editing by Gary Hill and Phil Berlowitz)

Stocks treated in this article : Citigroup Inc., International Business Machines Corp.