BEIJING (AP) _ Two Americans convicted of trying to swindle $10 billion from a Chinese bank lost their appeals Friday and were sentenced to prison.

It was one of the most serious swindles ever tried against a Chinese bank, and the sentences were among the heaviest given to American citizens in China.

Francisco Hung Moy, 45, and Raymond C. Lee, 44, Chinese-Americans who have lived in the New York area, are in a prison in Shijiazhuang, 170 miles southwest of Beijing. The official Xinhua News Agency said Moy was sentenced to 20 years and Lee to 14.

They were tried in April but the trial was not publicized until Friday. The U.S. Embassy in Beijing said consular officers had visited the men and had not seen any signs of mistreatment.

Xinhua said Moy and Lee told officials at a small-town branch of the Agriculture Bank of China they planned to invest $10 billion in China. They persuaded the officials at the branch in Hengshui, Hebei province, to issue them 200 standby letters of credit totaling $10 billion, giving as collateral a fake $10 billion letter of credit from a non-existent bank, it said.

A letter of credit is similar to a cashier's check, and usually is drafted by a bank on behalf of importers to pay for shipments of goods.

Xinhua said Moy and Lee planned to use the Chinese letters of credit to obtain a loan from a foreign company, and forged the bank's official seal to produce fake supporting documents. But the swindle was stopped before any of the Hengshui letters of credit could be cashed, and no money was lost.

The worst damage was to the credibility of the Agriculture Bank and Chinese banking as a whole. Just weeks before the Hengshui fraud was revealed in June, the Agriculture Bank was forced to issue a warning about another fraudulent, multimillion-dollar letter of credit issued by a rural branch.

The U.S. Embassy said it knows of fewer than half a dozen Americans in prisons in China. China frequently deports foreigners who commit minor offenses rather than holding them for trial.