Singapore's biggest sovereign wealth fund, Government of Singapore Investment Corp (GIC), said it converted its UBS notes into ordinary shares, suffering a paper loss of about $5 billion.
GIC had invested 11 billion Swiss francs ($10.22 billion) in mandatory convertible notes in UBS to support the Swiss bank during the financial crisis.
GIC did not provide more details, but a filing it made to the U.S. Securities and Exchange Commission early last month showed the original conversion price would be 47.7 Swiss francs, two-thirds more than UBS's last share price of 15.86 francs.
GIC had earned about 2 billion francs from a 9 percent coupon over the last two years, which partially compensated for the sharp erosion in UBS' share price.
"GIC confirms the conversion," a spokeswoman for the Singapore wealth fund said in response to Reuters' queries.