UPDATE 1-Malaysia's Maybank buys into Vietnam's An Binh Bank

(Adds details, quotes)

KUALA LUMPUR, March 21 (Reuters) - Malaysia's top lender, Malayan Banking Bhd (Maybank) (MBBM.KL), has agreed to buy a 15 percent stake in Vietnam's An Binh Bank for 430 million ringgit ($135.2 million) in cash, Maybank said on Friday.

The deal came just days after its nearest rival, Bumiputra-Commerce Holdings (BUCM.KL), said its main CIMB unit bought 20 percent of China's Bank of Yingkou Co for $50 million.

Malaysian banks are expanding abroad as earnings potential in their saturated home market slows. CIMB is one of the world's biggest arrangers of Islamic finance and also sees Yingkou as an opportunity to expand that business in China.

Maybank, which already has a presence in Brunei, Cambodia, Indonesia, the Philippines and Singapore, said the acquisition was part of its plan to expand in Southeast Asia.

"It is a strategic investment that we are making to expand our presence in Vietnam in line with our continuous effort to establish a stronger foothold in the regional markets," Maybank Chairman Mohamed Basir Ahmad said.

Set up in 1993, An Binh Bank has total assets of $700 million and 53 branches. Maybank said the number of branches would be raised to at least 150 by 2010.

Maybank said it might raise the stake to 20 percent with the approval of the Vietnamese government.

On Friday, Maybank shares closed up 0.6 percent at 8.75 ringgit a share, against the main index's .KLSE 2.5 percent rise. (Reporting by Jalil Hamid, editing by Will Waterman)