The much anticipated IPO of the world’s largest credit-card network has Visa selling 406 million Class A shares at between $37 and $42 each, for proceeds of $15 billion to $17.1 billion, according to a filing with the U.S. Securities and Exchange Commission. Visa said it might sell an additional 40.6 million shares to meet demand, which would increase the IPO's potential total to $18.8 billion.

If IPO goes as planned, it would vastly exceed the 2000 IPO by AT&T Wireless Group, which raised $10.6 billion. It would also be five times the size of smaller rival MasterCard Inc.’s IPO, which raised $2.4 billion in a May 2006.

Visa benefits as consumers use credit and debit cards more often. Citing the Nilson Report, a card industry newsletter, Visa said global card transaction volume may increase 11% a year from 2006 through 2012, with faster growth in the Asia/Pacific, Middle East/Africa and Latin America regions.

However, the timing of San Francisco-based Visa's offering is risky, as worries that the U.S. economy might be entering or is in a recession have chilled investor demand for stocks and IPOs.

"Visa is large, and has strong global growth potential," John Augustine, chief investment strategist at Fifth Third Private Bank in Cincinnati, told Reuters. "The downside to the Visa offering may be the timing. Our fear is that as credit deteriorates, consumer spending will go down, and volumes will go down for the card networks. That would hurt revenue and profit."