SINGAPORE, April 2, 2008 (AFP) - The Government of Singapore Investment Corp (GIC) stands by its decision to invest in troubled Swiss bank UBS and does not rule out a further capital injection, newspapers reported Wednesday.

UBS on Tuesday revealed an additional 19 billion US dollars in writedowns, making it the bank worst-hit by a global crisis that originated in the United States subprime, or higher-risk, mortgage sector.

The latest writedowns came on top of 18.4 billion dollars the bank wrote down in 2007, and which led it to seek an infusion of 11 billion Swiss francs (11.13 billion US dollars) from GIC.

Another two billion Swiss francs was to come from an unnamed Middle East investor.

'We recognise that there is impairment in the short term to our investment. However, GIC is a long-term investor and we maintain a positive longer-term outlook on the investment,' GIC spokeswoman Jennifer Lewis was quoted as saying in The Straits Times.

She could not be reached for comment on Wednesday.

UBS announced it is seeking to raise another 15 billion Swiss francs through a rights issue, and formed a new unit to hold currently illiquid US real estate assets.

Singapore's The Business Times quoted GIC as saying it 'will examine the terms of the rights issue and obtain other necessary information before we decide' whether to participate in the fund raising.

Under the earlier deal with UBS, GIC committed to subscribe to 11 billion Swiss francs worth of mandatory convertible notes that will pay a coupon of nine percent until conversion into ordinary shares about two years after issuance.

Depending on the conversion price, GIC saw its total shareholding amounting to possibly around nine percent of UBS equity but newspapers reported the newly-proposed rights issue could dilute GIC's stake.

The dilution is a 'necessary step' in the bank's long-term interests, The Straits Times quoted Lewis as saying.

A report by Citigroup Global Markets in October listed GIC as among the largest sovereign wealth funds in the world.