Tokyo-based NTT Communications has bought b-to-b Web site manager Verio Inc. for $5.5 billion in stock. The pact makes NTT, a unit of telecom giant Nippon Telegraph and Telephone Corp., Tokyo, an instant player in the U.S. Web hosting marketplace. NTT paid $60 per common share for Verio. In 1998, NTT bought 11.4% of Englewood, Colo.-based Verio for $100 million.