Prince George's County's new chief labor negotiator said yesterday that the county will offer its five unions of clerical and blue collar workers a 3 percent increase in wages in contract negotiations that begin Friday.

The five locals of the American Federation of State County and Municipal Employes in Prince George's, which represent 1,562 of the county's 6,299 employes, have received wage increases of 5 percent each year under 3-year contracts that expire this June.

But Joseph C. Fagan, who was appointed by County Executive Lawrence J. Hogan last month to manage county labor negotiations, said in an interview yesterday that the fiscal pressures on the county created by voter approval of a tax revenue freeze necessitated a smaller increase.

"If this were private industry we could negotiate an increase and pass it along to our consumers," Fagan said. "But we can't raise the price of our television sets this year."

Paul Manner, who will negotiate with Fagan on behalf of the five AFSCME unions under a new joint bargaining agreement, would not say yesterday what the unions would demand in wage increases this year. But he said of Fagan's suggested offer, "If he wants to cry poor man, then we'll expect to see the figures behind it."

Fagan also said that he would propose at Friday's bargaining session that negotiations be open to the public. Fagan said that public bargaining sessions were justified by heightened public interest in fiscal matters and would enable citizens to fully understand the positions of the unions and the county government.

"I'm surprised by that," Manner responded. "I've never bargained that way before." Manner said he would have to consult with AFSCME members before deciding whether to accept open bargaining.

"I think they'll realize that this will help their bargaining position in the end," Fagan predicted of the union leaders.

In addition to the AFSCME unions, Prince George's will negotiate new contracts with 6 other employe unions this year. Last year, the county spent $12.8 million on wage increases for employes under the old contracts.