China’s trade surplus widened to a record $14.5 billion in June as exports surged, increasing pressure on the government to let the yuan appreciate.

The surplus soared from $13 billion in May, beating the $12.8 billion median forecast of 26 economists surveyed by Bloomberg News. Exports jumped 23% from a year earlier, the Beijing-based Ministry of Commerce said yesterday on its Web site.

Inflows of foreign exchange have pushed China’s reserves to $875 billion, the world’s largest, and fueled an investment boom that has driven metals prices to records and threatens to fan inflation. Henry Paulson, who was sworn in as U.S.Treasury Secretary yesterday, on June 27 called for faster currency gains to redress a growing trade imbalance, as lawmakers seek sanctions against Chinese goods. “A high trade surplus is not in China’s own interest,” said Jonathan Anderson, chief Asia economist at UBS AG in Hong Kong. “They should continue to move to let the yuan appreciate faster.”

The central bank in April raised lending rates, and in June ordered banks to set aside more money as reserves.The bank has also sold domestic bonds to withdraw cash from the banking system and pledged to gradually loosen currency controls.

Besides driving up raw material prices and inflation, excessive investment threatens to leave China with idle factories, squeezing company profits, the central bank said last month. Premier Wen Jiabao has publicly rebuked commercial banks for extending too much credit for investment projects.

Exports climbed to $81.3 billion and imports gained 19% to $66.8 billion. The surplus in China, the world’s fastest-growing major economy, reached $61.5 billion in the first half, up 55% from the same period last year.

“We expect this will further stress relations with the U.S., especially as the trade surplus will continue widening in the second half” as the holiday shopping season approaches, an economist at Royal Bank of Scotland in Hong Kong, Ben Simpfendorfer, said.

China’s trade surplus, which tripled to a record $102 billion in 2005,may top $100 billion again this year as overseas companies build export factories there, an official at the statistics bureau, Zhai Zhihong, said in a report published June 23.

Mr. Paulson, former chief executive of Goldman Sachs Group Inc., said last month he believes China wants to adopt a fully flexible currency over the “intermediate” term. “We need to encourage them to move quicker,” he said.

“It’s time for China to move even further forward than it is in meeting the criteria for market economy status,” European Trade Commissioner Peter Mandelson said in an interview on July 7. “We are helping China in that direction but there’s more that China can do for itself.”