The Chesapeake & Potomac Telephone Co. and its union employes announced last night that they have reached an agreement averting a strike that had been set for Monday.

No details of the agreement in the dispute, which involved automation, were available last night from either the company or the union, District 2 of the Communications Workers of American AFL-CIO.

"We reached an agreement," said Ed Lewinski, chairman of the union's District bargaining committee and assistant to the Dictrict 2 vice president. d

"The strike is averted." He said details would be released Monday.

The dispute involved pay rates for two new positions created by the company in September, including a job in which clerical employes use a computer to do work previously done by technicians. The technicians have been paid $124 more a week than the clerical workers.

Also at issue was whether the company properly implemented the new positions.

According to a spokesman for the company, the federal National Labor Relations Board has upheld C&P's actions in creating the new jobs and hiring persons to fill them.

The union represents about 30,000 persons who hold jobs with C&P in the District, Maryland, Virginia and West Virginia. The union's contract with the company expires in August.

In preparation for a possible strike, C&P had begun handing out special assignments to supervisory personnel.

A company spokesman said last night that the cancellation of the threatened walkout followed "informal discussions" that continued yesterday into the early evening.