UPDATE 1-Natixis sees Taiwan offshore fund mkt up 15-20 pct

* Natixis asset mgmt says cross-straits ties to lift fund mkt

* Sees Taiwan as gateway to Asian markets, including China

* Opens Taiwan unit, third in Asia after Japan, Singapore

(Updates comments, adds details)

By Faith Hung

TAIPEI, Nov 5 (Reuters) - Natixis Global Asset Management (NGAM) (CNAT.PA), among the world's top 20 fund firms, expects Taiwan's offshore fund market to grow 15-20 percent in 2010 from about $65 billion now, as the island benefits from closer financial ties with China, a top executive said.

The French asset manager, aiming to cash in on improving cross-strait ties, will open a new Taiwan subsidiary -- its third Asia-based office after Japan and Singapore, and its first new regional office in 13 years.

Taiwan's roughly $52 billion fund market, one of the largest in Asia, is packed with global names including ING (ING.AS) Funds, BlackRock (BLK.N), Prudential Financial (PRU.N), UBS (UBSN.VX) and AIG (AIG.N), which are locked in tight competition to serve the island's investors.

NGAM managed $668 billion in client assets globally as of June.