Microsoft Corp. will acquire NetCarta Corp., a developer of Internet software, for $20 million in cash from direct marketer CMG Information Services Inc., the companies said Tuesday.

The news sent CMG stock up $1.75, or 10 percent, to $19-1/2 in trading on the Nasdaq Stock Market.

Microsoft plans to use NetCarta’s WebMapper Web-site management software in its Microsoft BackOffice suite, Dow Jones News Service reported.

CMG, of Andover, Mass., said Microsoft also agreed to acquire 4.9 percent of its outstanding shares.