Beijing  - Two major US financial firms are considering selling some of their shares in China's biggest commercial bank, the Industrial and Commercial Bank of China (ICBC), according to reports seen on Thursday.

A joint agreement on Wednesday leaves Goldman Sachs free to sell up to 20 per cent of its stake in ICBC, the Chinese bank said in a statement.

Goldman Sachs holds 4.93 per cent of ICBC's shares, with an estimated value of 7.5 billion dollars.

Under the new agreement, the US firm promised not to sell 80 per cent of its ICBC stake before April 28, 2010.

If it sells any of the remaining 20 per cent of its holding, Goldman Sachs will "explore all potential methods of sale that would maximize value and minimize market impact, with a preference for a private sale to investors", the statement said.

In a separate joint statement, American Express said it may sell the two halves of its 0.38-per-cent stake in ICBC once the agreed lock-up periods expire on April 28 and October 20.

ICBC quoted American Express as saying that "depending on market conditions the company may sell its ICBC shareholding at some point after the lock-up period."

American Express would also try to minimize market impact and preferred to sell to private investors, the Chinese bank said.

News of the possible sales follows several other high-profile sales of stakes in Chinese banks by foreign investors this year.

The ICBC recorded the world's biggest initial public offering when it raised 19.1 billion dollars in October 2006 in a dual-listing in Hong Kong and Shanghai. (dpa)