NEW YORK (Bloomberg) - American Express Co., the biggest US credit-card company by purchases and cash advances, said customers are falling further behind on their debt, signaling the economy is worsening.

"Business conditions continue to weaken in the US and so far this month we have seen credit indicators deteriorate beyond our expectations," CEO Kenneth Chenault said in a statement yesterday announcing the company would receive as much as $1.8 billion in a settlement with competitor MasterCard Inc.

American Express and rivals Capital One Financial Corp. and Discover Financial Services have fallen more than 30 percent in the past 12 months in New York trading as consumers absorb the housing slump, rising unemployment and higher food and fuel bills. New York-based American Express adopted a "cautious view" for the year in January after cardholder spending slowed and overdue payments rose in December.

"If you look at the employment situation, clearly that's deteriorated, and consumer confidence is down as well," said Sanjay Sakhrani, an analyst with KBW Inc. in New York who has a "market perform" rating on the stock. "Both play a key role in the credit-card industry."

The US lost jobs in May for a fifth month and the unemployment rate rose by the most in more than two decades. Payrolls fell by 49,000 after a 28,000 drop in April, the Labour Department said June 6. The jobless rate increased by half a point to 5.5 percent.

Confidence among Americans dropped to the lowest level in 16 years, the Conference Board said on Tuesday.

American Express declined 20 cents to $41.90 at 11.30am in New York Stock Exchange composite trading.

First-quarter loss provisions in the company's US card business rose 52 percent to $881 million as net income declined 11 percent to $974 million.