Henry Paulson was sworn in as the 74th US treasury secretary yesterday and was immediately urged to keep pressure on China to increase the flexibility of the yuan.

This morning the yuan stood at 7.9922 to the dollar and at 14.7210 to the pound.

Henry Paulson, 60, is a former chief executive of investment bank Goldman Sachs and takes over from the oft maligned John Snow.

His nomination was backed by both Republicans and Democrats.

One of his biggest challenges as he takes up his new role is pressing China on its currency. US manufacturers complain that China undervalues its currency by 15 to 40 per cent, giving Chinese companies an unfair price advantage.

"I'd like to have him be very, very tough on China's currency issues,"

senate finance committee chairman Charles Grassley said in an interview on CNBC.

At his swearing in ceremony Mr Paulson said: "We must always remember that the strength of the US economy is linked to the strength of the global economy.

"If we retreat from the global stage, the void is likely to be filled by those who do not share our commitment to economic reform."

President George W Bush added: "He will work to keep this economy of ours competitive and growing, and he will work to ensure fair treatment for America's goods and services across the world."