(Reuters) - Citigroup's ( C/PN ) Titi Cole, a top executive in charge of implementing its sweeping restructuring plan, is leaving the bank, an internal memo seen by Reuters showed on Tuesday.

Cole, as the head of legacy franchises, executed the third largest U.S. lender's plan to simplify the firm by completing the sales of consumer banking businesses in nine non-core markets.

CEO Jane Fraser began a sweeping reorganization in September to simplify the bank and improve performance. Investors have rewarded Fraser with a boost in the share price since the overhaul began.

The bank has shed legacy businesses in several international markets in recent years and has plans to offload its Mexico consumer banking unit, Banamex, in 2025 through an initial public offering.

Cole, who spent four years at Citi, is taking the role of an executive director at a non-profit focused on women and healthcare.

Citi also announced Mike Whitaker, head of the bank's operations and technology team, is leaving after a 16-year stint at the bank.

Tim Ryan, who most recently led PwC's U.S. franchise as senior partner, will become Citi's head of technology and business enablement. Ryan will also join the lender's executive management team.

(This May 14 story has been corrected to say Titi Cole spent four years at Citi, not 30, in paragraph 5)