Six of the seven Baby Bell companies face a strike.

The Communications Workers of America, which represents 262,000 communications workers nationwide, is negotiating at 48 tables around the country with representatives of Southwestern Bell, Nynex, Ameritech, US West, Bell Atlantic and Bell South. Pacific Telesis announced an agreement with the union Monday. All units of the union have authorized their leaders to call a strike after their contracts expire at midnight Saturday if they are not satisfied with the progress of talks, said Rozanne Weissman, a spokeswoman at the union’s headquarters in Washington.