NEW YORK (AP) _ VeriSign Inc., a leading provider of Internet encryption technology, is buying Network Solutions Inc. in a $21 billion deal aimed at offering businesses a range of Web services, from setting up Internet sites to securing transactions.

Network Solutions once was the sole registry for domain names on the Internet. But since the registration market was opened last year to competition, the company has been selling additional services, such as helping companies start Web sites and security services.

VeriSign, for its part, has attracted growing demand for its range of sophisticated encryption products and consulting services, which help businesses encode e-mail, Web site transactions and sensitive Internet information.

The deal announced today combines companies whose security services ``support businesses and consumers from the moment they first establish an Internet preserve,'' the companies said in a statement.

Under the deal, VeriSign, based in Mountain View, Calif., will issue 2.15 shares of its stock for each share of Network Solutions that existed prior to a 2-for-1 split due to be completed on Friday. Network Solutions is based in Herndon, Va.

On Monday, shares of VeriSign were priced at $247.43 3/4 at 4 p.m. EST on the Nasdaq Stock Market, down $1.06 1/4 or 0.4 percent, for the day. Shares of Network Solutions were at $360.62 1/2, up $4.93 3/4 or 1.3 percent, also on the Nasdaq.

The acquisition is expected to close in the third quarter.

In their statement, the companies said that the deal already has been approved by both companies' boards and must be voted on by shareholders.

The statement said Network Solutions will become a subsidiary of VeriSign and that Network Solutions chief executive officer Jim Rutt will continue as CEO of the subsidiary.