(Adds details from UBS statement, background)
ZURICH, May 15 (Reuters) - Singapore sovereign wealth fund GIC Private Limited, that helped to support UBS as the financial crisis hit, plans to sell a stake of up to 2.4 percent in the Swiss bank.
UBS, the world's biggest wealth manager, said on Monday GIC intended to place up to 93 million existing shares in UBS Group through a sale to institutional investors.
UBS shares closed 1.3 percent lower at 16.61 Swiss francs after the news, which unusually came during trading hours. GIC's stake will be under 3 percent when the sale is completed, UBS said.
At the closing price, 93 million shares would be worth around 1.54 billion Swiss francs ($1.55 billion).
GIC was not immediately available to comment.
GIC, owned by the government of Singapore, was one of the first sovereign funds to pump billions into Western banks, which were rocked by the 2008-2009 financial crisis and suffered deep losses.
Singapore had taken a 9 percent stake in UBS in 2007 via an emergency capital injection when UBS unveiled $10 billion worth of subprime writedowns.
In 2010, GIC converted 11 billion Swiss francs worth of UBS notes into shares.
UBS's website listing major shareholders said that Singapore as the owner of GIC had held a stake of 7.07 percent as of December 2014.
GIC's website says it has more than $100 billion of assets in over 40 countries.
GIC Private Limited and its associates have agreed to a 90-day lockup period for the remaining UBS shares, UBS said.
UBS Investment Bank is acting as placement agent on the sale.
($1 = 0.9962 Swiss francs) (Reporting by Michael Shields; Editing by David Goodman and Jane Merriman)