Prince George's County Executive Parris Glendening signed a two-year contract this week with three union locals representing 634 county workers, almost four years after bitter negotiations between former executive Lawrence J. Hogan and the American Federation of State, County and Municipal Employees began.

The contract, which provides a wage settlement of approximately $1.1 million retroactive to July 1981, brings to an end the longest labor dispute in county history, Glendening said.

The settlement, based on a tentative 1980 agreement that Hogan refused to sign, was reached after two days of talks with Glendening's new chief labor negotiator, Frank W. Stegman. A county circuit court judge had ordered Hogan to sign the contract, but it was never implemented, and the money had been sitting in an escrow account.

The affected union members will receive a 5 percent cost-of-living increase for fiscal 1982 and a 7 percent increase for 1983, the current budget year. The settlement, including approximately $136,000 in interest, according to Stegman, amounts to about $2,000 per worker.

The locals affected represent about 450 employes in public works, 71 clerical workers and professionals in the departments of aging and program planning, and 113 housing and street inspectors, county officials said. The increases are identical to raises given non-union county employes for those years, but Glendening stressed that a similar hike for 1984 would be "unrealistic."

"We don't want it to look like we're giving these guys 7 percent and are crying poor out of the other side of our mouths," said Glendening aide Michael Knapp.

AFSCME leaders, who backed Glendening early in his bid for the executive seat, hailed a new era of labor conciliation. Without a contract, the locals have collected no dues since August 1980. One local, representing 200 to 400 clerical workers, opted out of the union in 1981. Another, representing workers at the county detention center, folded that year after 37 jail guards were fired following a strike.

"I've been in the union since 1943. I've dealt with some of the toughest and roughest in both the public and private sector," said AFSCME state council head Ernie Crofoot. "This the Hogan years is the absolute worst we've ever had."

With Glendening in office, "there's a big difference in attitude and atmosphere," said Sylvia Reicher of Local 1691, who participated in the negotiations with both administrations.

Reicher, a social worker with the Department of Aging, said she did not know where to start spending her money. "I can pay bills that have been sitting around," she said. "And my kids and I can go out to dinner."