* Banga named MasterCard COO, effective Aug. 31

* Was previously Citigroup's Asia chief

* To receive $4.2 mln sign-on bonus

NEW YORK, June 19 (Reuters) - Citigroup's (C.N: Quote, Profile, Research) Asia head, Ajay Banga, will join MasterCard (MA.N: Quote, Profile, Research) as its president and chief operating officer, the latest in a series of high-profile departures from Citigroup.

The appointment puts Banga in line to become the chief executive officer of the world's second-largest credit card network.

"While this was not the appointment of a CEO successor this was certainly the appointment of someone who fits in to a very thoughtful succession plan for the company," MasterCard spokesman Harvey Greisman told Reuters.

Banga, 49, can leave the company with his upfront compensation intact if he is not offered an opportunity by June 30, 2010 to become succeed Robert Selander as CEO of MasterCard.

Selander, who has led MasterCard since April 1997 and oversaw a high-profile public listing of the company in 2006, will relinquish the title of president to Banga when he joins the firm on Aug. 31.

MasterCard will pay Banga a $4.2 million sign-on bonus and $4.9 million in restricted stock grants, according to a regulatory filing.