The Austin, Texas-based company said it will power part of Microsoft's MSN MoneyCentral site, one of many personal finance sites dispensing information on investing, banking, taxes and related topics.
Hoover's will primarily supply information to the new MoneyCentral IPO Center, which includes information on companies that have filed to go public and the performance of recent initial share sales.
The announcement sent Hoover's stock up $1.63 to $12.75 on volume of 1.2 million shares, more than five times its average daily volume.
Hoover's spokeswoman Lisa Glass said the deal involved a payment between the two companies but would not disclose further details.
Hoover's also publishes a financial research Web site that offers information and business products. Some of the site's content is free, while other parts require a membership fee.
Hoover's reported $9.2 million in sales for 1999 and net loss of $2.3 million. The company went public July at $14 a share; it has traded as high as $33 and as low as $8.13.
Hoover's also has content deals with America Online, Yahoo, Bloomberg News and Dow Jones. Time Warner subsidiary Warner Books owns an 18 percent stake in Hoover's; Media General owns 13 percent.