UPDATE 1-Strong debut for South Korea's Netmarble Games after mega IPO

* S.Korea's 2nd-largest IPO ever

* Proven ability to release continuous hits-analysts

* War chest of $4.4 bln for acquisitions-company (Adds analyst quote, game releases, share supply, M&A plan)

SEOUL, May 12 (Reuters) - Shares in Netmarble Games Corp debuted as much as 9 percent higher on Friday, as investors sought to buy into the success of the smartphone games maker which last month raised $2.3 billion in South Korea's second-largest initial public offering.

The stock opened at 165,000 won ($146.65), some 5 percent higher than the IPO price of 157,000 won, rising to as high as 9.2 percent in early trade. The KOSPI index was down 0.3 percent as of 0025 GMT.

Netmarble has lured investors in the crowded gaming market by steadily churning out hits.

Its role-playing game "Lineage II: Revolution" became the world's best-selling mobile game in February even though it is only available in South Korea, while subsequent release "PentaStorm" is the most popular game on Google Android's South Korea store as of Friday.

A shortage of tradeable shares is also helping support the stock, brokers said.

About 17.6 million shares out of 84.7 million total are available for trade, with the rest - almost all owned by controlling and strategic shareholders such as Netmarble founder Bang Jun-hyuk and Tencent Holdings - in a six-month lock-up.

"Compared to other Asian game developers such as Mixi or GungHo that have not had a notable follow-up after they released mega-hit games, Netmarble has steadily released hits," said Shinyoung Securities analyst Jang Won-yeol.

Netmarble said in April it expects to have a war chest of some $4.4 billion for acquisitions after the listing to realize its goal of becoming one of world's top five games companies by 2020 with 5 trillion won in annual revenue.

The company had priced its April IPO at the top of an indicative range.

($1 = 1,125.1600 won) (Reporting by Joyce Lee; Editing by Miral Fahmy)