Goldman Sachs International sold HK$3.73 billion ($478.7 million) worth of shares in Industrial and Commercial Bank of China Ltd, the world's largest lender by market value, in what it said was a transaction to help a client hedge its position in the bank.

Goldman sold 638.06 million Hong Kong-traded shares of ICBC (1398.HK) at a price of HK$5.84 each, a 2.5 percent discount to Monday's closing price of HK$5.99, according to a term sheet of the transaction sent to investors late on Monday.

A source familiar with the deal told Reuters on Monday that Goldman acted on behalf of American Express (AXP.N).

American Express held 638.06 million shares in ICBC, equivalent to a 0.74 percent stake, at the end of December, according to Thomson Reuters data.

The term sheet said Goldman was acting on behalf of a client to facilitate a hedging transaction, without disclosing the name of the client. The U.S. firm was the sole bookrunner for the deal.