RICHMOND, SEPT. 4 -- Virginia Attorney General Mary Sue Terry has hired William G. Thomas, an Alexandria-based lawyer and lobbyist who raised funds for her election campaign, to help solve a year-long dispute over the handling of a $42 million state employe pension fund.

Terry's decision to hire Thomas, which drew criticism from some senior state officials, reflects the attorney general's intent to take legal action against the Hartford insurance group, which administers the retirement fund for 3,000 of the state's roughly 90,000 employes, officials said.

Thomas, a personal friend of Terry's who in the past has generally shunned government work, today defended the hiring and his $100-an-hour fee, as did a spokesman for the attorney general.

"The obvious political advantage would be to handle the case in-house," said Bert L. Rohrer, Terry's press secretary. But, he added, "The attorney general deemed it prudent lawyering to have a cocounsel."

Rohrer suggested strongly that Terry's office is prepared to file a lawsuit against the Hartford group to resolve dozens of state employe complaints about the performance of the Connecticut-based insurer in overseeing the fund. Outside counsel is needed, Rohrer said, because members of the attorney general's office who helped negotiate the state's contract with Hartford could be called as witnesses in a legal proceeding, Rohrer said.

Thomas, whose law firm is the third largest in the state, is one of the most successful lobbyists before the Virginia General Assembly, representing such corporate giants as Blue Cross-Blue Shield and Mobil Corp.

As a high-profile go-between for the state's commercial and political establishments, he has been a confidant to former governor Charles S. Robb, Gov. Gerald L. Baliles and other prominent Democrats.

"Mary Sue is a friend and I've tried to help her when she asked me to over a number of years," Thomas said in a telephone interview today. "There isn't any question" of impropriety in his hiring, he added, noting that the $100 hourly fee he will charge the state is considerably lower than his going rate.

"The issue is whether our firm is competent to handle the matter," Thomas said. His firm is "pretty knowledgeable" about employe compensation issues, having represented the Public Employees Benefit Services Corp. in its unsuccessful attempt to win the contract that eventually went to the Hartford group in 1984, Thomas added.

Lewis S. Minter, the general counsel of the State Corporation Commission who has criticized the Hartford group's performance, said he believed that Thomas could not be "independent" as cocounsel because of his ties to Richmond's corporate elite and former Robb administration officials who approved the Hartford contract.

"In my judgment, he's too tied in with the crowd that's running it," Minter said. "It's putting the fox in to guard the henhouse."

Del. Theodore V. Morrison Jr. (D-Newport News), who sponsored legislation this year giving state government workers the right to participate in compensation programs other than Hartford's, also was sharply critical of Terry's decision to hire Thomas.

"I didn't know Bill Thomas needed the work that badly. I thought he was pretty well-heeled," said Morrison, who has tangled with Terry's office on a host of issues.

Morrison said the Thomas hiring was "another example of the too-frequent retaining of outside counsel when the attorney general's budget is higher than it's ever been and they've got more people than they ever had."

Another critic of the Hartford group, state Senate Clerk J.T. Shropshire, took a somewhat more politic view of Thomas' hiring.

"If the attorney general has hired Bill Thomas and he can help state employes get their money rolled over to another fund, then I applaud them both," said Shropshire, who has tried for weeks to extricate his savings from the Hartford plan.

"I'll be among the first to wave the flag for 'em."