Mediators in contract negotiations between Prince George's County and five union locals said yesterday they have abandoned efforts to resolve wage disputes, creating the possibility of a strike by 1,500 county employes.

The mediators asked the County Council to make a final attempt to negotiate a contract with the locals in the American Federation of State, County and Municipal Employees.

By yielding authority in the dispute, the mediators, who were hired by the county, have started a 70-day countdown after which the union legally can strike. If the council agrees to act as a mediator, the union can strike in 40 days.

Council members said they have not decided whether to get involved. This is the first time that a contract dispute in Prince George's County reached the criticial last step of council involvement, council officials said.

Yesterday, the presidents of the five locals and the county representative of the federation said they welcomed council involvement in the negotiations, but they thought a strike in February or March was "a good possibility."

Paul Manner, the federation representative, said "We have tried everything else and this [a strike] looks like it's it. We will ask other unions not to cross the picket line."

Contract negotiations between the county and the union have been under way since February. However, employes in the county departments of corrections, licenses and permits, public works, housing and aging and clerical staff, who are represented by the union, have been working without a contract since July, when their previous agreement expired.

Negotiations have foundered on the issue of cost-of-living raises. County Executive Lawrence Hogan has offered the union a 4.7 percent increase similar to what other nonunion employes were given last July, but he wants to be able to renegotiate that amount after the first year of a new contract.

Manner said that the 4.7 percent increase was not acceptable at a time when inflation is more than double that amount. In addition, he said, the union would not agree to a "reopener" clause.

The federation and other county unions have consistently criticized Hogan for being "antilabor."

"He thinks it's politically popular to beat up on public employes, Manner said. "He's using public employes as a whipping boy for his political aspirations."

Hogan has said that the unions demanded too much and his offers are fair and adequate given the strict financial limitations imposed on the county by the tax-limiting TRIM charter amendment.