SBC Communications Inc. and the union representing 100,000 of its workers agreed on Friday to a day-to-day extension of talks on new contracts, hours before a midnight deadline for a possible strike.

Contracts between the Communications Workers of America and SBC, the second-largest U.S. telephone company, expired last month without new agreements. The two sides have sparred over health-care benefits and job security in the shadow of an industry facing declining revenues and growing competition.

The contracts under negotiation cover workers in 13 states, including Kansas. The union represents about 100 workers in the Lawrence area.

The CWA told its members on Friday that the two sides had agreed to extend talks on a day-to-day basis. It had said it could strike after midnight if no agreement was reached, but said it would now give the company a 24-hour notice before walking out.

The federal mediator overseeing the negotiations said top officials from the company and union would meet with him Monday in a special “high-level” session.

Talks have taken place during the past few days. But the CWA told its members late Thursday that progress since then was “minuscule,” and that SBC’s responses to the union’s proposals were “perplexing.”

SBC did not immediately return calls for comment.

Health care for current employees and retirees has emerged as one of the thorniest issues for the two sides, just as it did in the union’s negotiations with Verizon Communications Inc. last year. The two sides were able to reach an agreement last week on retiree health care.

The CWA also wants SBC to put more union workers in growing parts of SBC’s business, such as high-speed Internet access.

SBC has offered greater job protections for current workers who might face layoffs.