UPDATE 1-AmEx sees less pain than rivals from new law

* American Express looks to expand charge card business

* Tighter regulation coming

* Shares fall 1 percent to $24.47

NEW YORK, June 3 (Reuters) - American Express Co AXP.N said on Wednesday that it would suffer less than its rivals from a new U.S. law curbing certain practices by credit card companies because it depends less on interest paid by customers.

Chief Executive Kenneth Chenault said that while American Express received only 20 percent of its revenue from charging interest rates, rivals JPMorgan Chase & Co JPM.N, Citigroup Inc C.N, and Bank of America Corp BAC.N made the bulk of their credit card revenue from that single item.

“We will suffer less pain,” Chenault said during a conference organized by Keefe, Bruyette & Woods.

The new law, due to take effect in February 2010, will restrict the ability of credit card issuers to raise interest rates on cardholders’ existing balances, to charge certain fees, and to impose penalties on consumers that the government deemed unreasonable.

In addition, Chenault said the largest U.S. credit card company by sales was planning to aggressively promote its charge cards -- whose balance must be paid in full at the end of the month -- as debt-burdened American consumers try to deleverage and use their credit cards less.

Citigroup, Bank of America, JPMorgan, American Express, Capital One Financial Corp COF.N, and Discover Financial Services DFS.N have more than 80 percent of the U.S. credit card industry.

American Express shares fell 1 percent to $24.47 in afternoon trading on the New York Stock Exchange. However, the stock is up 32 percent in 2009. (Reporting by Juan Lagorio; Editing by Toni Reinhold, Bernard Orr and Lisa Von Ahn)