Visa Inc. said today that it might raise up to $18.8 billion in the largest initial public offering ever, Reuters reported. The world’s largest credit card network filed with the U.S. Securities and Exchange Commission to sell 406 million Class A shares at $37 to $42 each, resulting in $15 billion to $17.1 billion of proceeds.

San Francisco-based Visa said it might sell another 40.6 million shares to meet demand, boosting the IPO’s potential size to $18.8 billion. This Visa IPO would beat the $10.6 billion offering in 2000 by AT&T Wireless Group. Visa plans to list on the New York Stock Exchange under the symbol “V.”

The timing of Visa’s offering is risky, as worries that the U.S. economy might be entering a recession have chilled investor demand for stocks and IPOs. “Visa is large, and has strong global growth potential,” said John Augustine, chief investment strategist at Fifth Third Private Bank in Cincinnati. “The downside to the Visa offering may be the timing.”

Investors may hope Visa shares will fare as well as those of smaller rival MasterCard Inc.

MasterCard shares have more than quintupled since that company went public in a $2.4 billion IPO in May 2006. In the fourth quarter of 2007, Visa posted a net income of $424 million on revenues of $1.49 billion, according to the SEC filing. MasterCard posted a net income of $304.2 million on revenues of $1.07 billion.