Visa Inc. said Monday its initial public offering could raise up to 9 billion - making it the largest in U.S. history - even though the credit-card processor is entering the market amid difficult economic times. Banks that issue Visa cards are expected to see a windfall of more than 0 billion.

New York ? Stocks are shaky, credit is tight, the economy may be tipping into a recession. Not the best of times to be going to the markets for what could be the largest initial public offering in U.S. history.

That’s the gamble Visa is taking as it gave details Monday about an IPO that could raise up to nearly $19 billion: If it works, it could be an encouraging sign to the stock markets and may even help loosen the credit knot.

While Visa’s IPO will have little direct effect on its cardholders, the banks that issue Visa cards are expected to see a total windfall of more than $10 billion – which might keep them from pulling back credit lines further and pushing rates higher.

“That’s a good thing for the banks and a good thing for consumers. It might help ease the credit crisis a bit,” said Ben Woolsey, marketing director at the card information Web site CreditCards.com.

Banks have suffered huge losses tied to defaults on subprime housing loans and are gearing up for more as consumer credit deteriorates. JPMorgan Chase & Co. – which has a 23 percent stake in Visa – stands to gain the most. The more cash-strapped Citigroup Inc. and Bank of America Corp. are also Visa stockholders.

Expected release in March

Visa said Monday in a Securities and Exchange Commission filing that it will offer 406 million shares at $37 to $42 each, following its rival MasterCard in shifting from being a privately held interest to a publicly traded company. If there is enough demand for Visa stock, underwriters will have the option to buy an extra 40.6 million shares.

The San Francisco-based company would not say exactly when it planned to float its shares, but IPO research firm Renaissance Capital, based in Greenwich, Conn., said it believes the offering will price on March 19 to begin trading March 20.

Demand for IPOs has been incredibly weak recently, reflecting nervousness among investors about placing bets in untested waters.

Last year at this time, IPO returns were outperforming the broader stock market, and now, they’re underperforming. The number of companies going public has dwindled to 18 so far this year from 34 at the same time in 2007, according to Renaissance Capital, which operates IPOhome.com.

A robust Visa IPO “could be the spark that is needed,” said Kathy Smith, a principal at Renaissance Capital. “It shows that there is a belief that investors want to put new capital to work in this company.”

Strong demand expected

Visa expects to see high demand for its stock despite the housing-led credit squeeze that is threatening consumers’ spending and their ability to keep up with debt payments.

Like MasterCard Inc., Visa is a card processor – not a lender – so it makes its money through fees from the banks issuing its cards and the merchants accepting them. And like MasterCard, Visa could see more struggling consumers increasingly use their cards for such high-cost necessities as health care, food and gasoline, which could boost the fees Visa earns.

Delaying the IPO process would “be like turning around a massive steamship and could raise speculation about what’s wrong,” Woolsey said. The company has been planning for an IPO this year since a filing with the SEC in June.

Another possible reason to get the IPO done this spring is this summer’s Olympic Games in Beijing, for which Visa is an official sponsor and the exclusive credit card provider.