Knight-Ridder is closing its videotext service.

The 2 1/2-year-old Viewtron computer videotext service will be shut down within weeks because it’s not making a profit, the Knight-Ridder Newspapers announced. Viewtron was launched in October, 1983, and grew in the last six months to more than 20,000 subscribers from about 3,000, the company said. Viewtron employs 139 people, who will be laid off.