UPDATE 1-Mastercard chairman Banga to retire at year-end, Janow to head Board

(Adds background on Janow)

Sept 21 (Reuters) - Mastercard Inc said on Tuesday Chairman Ajay Banga would retire on Dec. 31, nearly a year after he stepped down as the payment processor's chief executive.

The company said current lead independent director Merit Janow would be the non-executive independent chair and would assume her new role on Jan. 1, 2022.

Janow, who joined the board in 2014, is also a dean and professor of international economic law and international affairs at Columbia University's School of International and Public Affairs, the company said in a statement.

Earlier this year, Banga stepped down from his role as the CEO of the payments processor. He was replaced by company insider Michael Miebach.

Banga had taken charge of the company just after the 2008-09 financial crisis. During his tenure as the top boss, Mastercard's revenue tripled as online shopping gained prominence around the world.

(Reporting by Niket Nishant in Bengaluru; Editing by Krishna Chandra Eluri)