The United States is ratcheting up pressure on Japan to toughen its penalties for bribing foreign government officials, in an apparent bid to ensure a level playing-field for American companies in the global marketplace.

At a series of high-level trade talks held in recent months between the two countries, the U.S. administration of President Bill Clinton has complained about what it views as lenient Japanese penalties for individuals and companies found to have bribed foreign government officials to win business contracts, according to government sources.

"The U.S. is probably concerned that Japanese companies may gain an unfair competitive advantage over their American rivals, especially in the Asian markets, which are rapidly recovering from the 1997 economic crisis," a senior official at the Ministry of International Trade and Industry said, requesting anonymity.