UPDATE 1-Outgoing Singapore Air CEO to become new SGX chairman

* Chew Choon Seng to become chairman on Jan 1, 2010

* Replaces J.Y. Pillay who is retiring

(adds details of new chairman)

SINGAPORE, Sept 6 (Reuters) - Singapore Exchange (SGXL.SI), Asia's second-largest listed bourse operator, said on Monday that Singapore Airlines (SIAL.SI) CEO Chew Choon Seng will become its chairman from Jan 1, replacing J.Y. Pillay who is retiring.

SIA, Singapore's flag carrier, said last week that Chew will retire at the end of this year. Chew, 63, has been on SGX's board since December 2004. [ID:nSGE6820EE]

Chew, who has a masters degree from Imperial College London, is also a director of the Government of Singapore Investment Corp, the city-state's giant sovereign wealth fund.

Pillay, 76, was appointed SGX chairman in November 1999. He was a top civil servant and his previous positions included the chairmanship of SIA. (Reporting by Kevin Lim)