UPDATE 2-Capital One credit card defaults rise in May

* U.S. credit card default rate rises to 9.41 percent

* International card default rate rises to 9.77 percent

* Shares fall 1.8 percent to $23.50 in premarket trading (Updates with analyst comment, stock fall, byline)

NEW YORK, June 15 - Capital One Financial Corp's U.S. credit card defaults rose in May as unemployment increased and Americans struggled to pay their debts, the company said on Monday.

Defaults climbed even though the issuer of MasterCard and Visa credit cards changed its customer bankruptcy accounting and now is waiting longer to declare the debts of bankrupt customers uncollectable.

In a regulatory filing, Capital One said the annualized net charge-off rate for U.S. credit cards -- debts the company believes it will never collect -- rose to 9.41 percent in May from 8.56 percent in April.

The company said the accounting change had improved its charge-off rate by 50 basis points. Excluding the change, the rate would have been close to 10 percent.

Still, Capital One is performing better than bigger rivals American Express Co, Citigroup Inc and Bank of America Corp, whose default rates already exceed 10 percent.

Capital One said credit cards at least 30 days delinquent -- an indicator of future loan losses -- fell for third straight month, to 4.90 percent in May from 5.04 percent in April.

Credit Suisse analyst Moshe Orenbuch said Capital One's quarter-to-date losses were trending below his forecast. But he expects the loss rate in U.S. cards to top 10 percent in coming months and to peak in the third quarter.

For U.S. auto loans, Capital One's charge-off rate rose to 3.62 percent in May from 3.46 percent in April, while the delinquency rate increased to 8.59 percent from 7.81 percent.

In international operations, including Canada and Britain, the charge-off rate rose to 9.77 percent in May from 8.91 percent in April, while the delinquency rate increased to 6.69 percent from 6.43 percent.

Capital One reported a higher-than-expected first-quarter loss, hurt like most of its rivals by growing credit losses and higher provisions for bad loans. It was only the second quarterly loss for the company.

However, U.S. regulators have declared the bank sufficiently capitalized to face a deep recession, and Capital One is expected to soon repay the $3.55 billion it received under the government's bank bailout program.

The bank once specialized in credit cards but expanded into branch banking in recent years after acquiring Hibernia Corp and North Fork Bancorp Inc. More recently, the acquisition of Chevy Chase Bank expanded its presence in the affluent suburbs of Washington, D.C.

Capital One shares fell 1.80 percent to $23.50 in premarket trading. The stock is down 25 percent this year but has more than tripled in price in the past three months, coming off a 13-year low.