Early last month, Rep. Frederick C. Boucher, a young, liberal Democrat from Southwest Virginia, sat through an unlikely meeting with a group of conservative Richmond financiers.

Huddling over breakfast at a Richmond eating club, Boucher touted a probusiness bill he has introduced in Congress that would weaken attempts to bring civil racketeering cases against securities brokers, accounting firms and banks.

"We were delighted and appreciative," said Walter W. Craigie Jr., an executive with Wheat, First Securities Inc., and a prominent Republican.

Boucher has been popping up recently all over Virginia at fund-raisers in Fairfax County, breakfasts in Roanoke and gatherings in Richmond, according to Democrats and Republicans. The appearances, they say, mean that Boucher has started running, unofficially, for the U.S. Senate seat held by Paul S. Trible Jr., a Republican freshman who is up for reelection in 1988.

"Boucher told me that he was interested in running for the Senate. That was two years ago," said state Democratic Party chairman Richard J. Davis, the former lieutenant govenor who ran against Trible in 1982.

In a recent interview, Boucher was reticent. "I've been flattered that I have received calls from quite a number of Democrats who have asked that I run for the Senate in 1988," he said. His decision will be based, he added, on "whether I can provide a more valuable service by remaining in the House or by seeking a seat in the Senate."

Boucher, 39, with a boyish face, pin-striped attire and horn-rimmed glasses, presents an anomalous image, given his rural background. His reserved and carefully controlled style seems more Wall Street than Southwest Virginia, where the passion of politics has earned his congressional district the nickname "the Fighting Ninth."

Boucher, in fact, was a Wall Street lawyer. He left to be an advance man for George McGovern's 1972 presidential campaign and then returned to Abingdon, Va. But Boucher's political roots in Southwest Virginia run deep: His grandfather and great-grandfather were members of the House of Delegates, and his father was Washington County's commonwealth's attorney.

Some Democrats fear that he is too liberal for Virginia, although Boucher has always eschewed that label, saying that he merely reflects his historically progressive Appalachian district. More recently, however, some measures that have occupied his time, such as the racketeering law, have had a decidedly probusiness tinge.

A few senior Democrats have said it might be premature for Boucher -- the youngest member of the state's House delegation -- to test the Senate waters. And some say that he is too much like Trible -- young, ambitious and with a slightly wooden style. But while Boucher is hardly a household name in Virginia, he served seven years in the state Senate and appears to be well known and well liked among most party regulars.

Nevertheless, Boucher is, at most, the party's second choice, lagging far behind former governor Charles S. Robb. Robb, however, has told anyone who has asked that he is not interested in a Senate race, and many people, including Boucher, are promoting Robb for vice president.

"What I hear as I talk to my friends on the floor of the House is that Chuck Robb seems to be virtually everyone's choice for vice president in 1988," said Boucher. "And, indeed, I think there's a lot of wisdom in that."

The second choice of some Democratic Party officials for the Senate race is Rep. Norman Sisisky, a wealthy soft drink executive from Petersburg who has business experience, strong ties to the black community and a gregarious style. But Sisisky has said he would prefer the governorship to the Senate, if he were to make a statewide bid.

In recent months, Dr. Ronald Dozoretz, a wealthy Norfolk psychiatrist and Democratic fund-raiser, has talked about a Senate race, according to Davis, the Democratic Party chairman. Dozoretz is president of First Hospital Corp., which owns 10 private psychiatric hospitals. He has never run for office, but Democrats say his ability to sink substantial amounts of his own money into the campaign makes him a credible contender.

Money is one reason Democrats are starting to line up potential candidates now, more than two years before the race. Davis estimated that the race will cost Democrats $4 million. Boucher said he would need to raise $2 million to $3 million. Trible is expected to begin amassing a considerable war chest to try to scare off a strong challenge.

Boucher has not started raising money, but he has raised his profile, traveling the state and taking on more visible and controversial issues. In the past year, he:

*Sponsored a bill that meant a head-on clash with Sen. John W. Warner (R-Va.) on the emotional issue of "atomic veterans." Veterans who believe they were harmed by atomic weapons testing have rallied angrily against Warner for sponsoring a law that prevented them from going to court to win damages. Boucher's bill would let atomic veterans sue the government.

*Joined Rep. Henry J. Hyde (R-Ill.) to push for a bill that has angered music composers and publishers. The measure would allow television stations to buy syndicated programming without paying separately for the music sound track.

*Led the fight to weaken the civil section of the Racketeer Influenced and Corrupt Organizations Act. The law enables someone injured by a "pattern of racketeering" to sue for triple damages. The measure was aimed at combatting organized crime, but an American Bar Association survey has found that 40 percent of the cases brought are for securities fraud and 37 percent are for commercial or business fraud. Boucher's bill would allow civil racketeering suits only against a company or individual with a criminal conviction.

The highly publicized racketeering fight, in which he has drawn praise and fire, is expected to be Boucher's political mine field in the next year. His skill at maneuvering through this controversy may determine his standing in the Senate sweepstakes, according to some Virginia congressional aides.

A wide range of business and labor groups have enthusiastically backed the bill, and only a few months ago victory appeared imminent. But district attorneys, attorneys general, the Justice Department and a Ralph Nader advocacy group have lined up on the other side, warning that Congress would be eliminating a powerful weapon against corporate fraud.

"I don't deny that it's an effective antifraud remedy. The problem is it's too effective," said Boucher. "It's too broad and unstructured."

Despite the opposition, Boucher said he is confident that Congress will enact his bill. He said he is less definite about his career plans.

He brushed aside questions of fund raising, the depth of his support and his personal ambition, insisting that his decision to run for the Senate would be based not on what he could gain but on what would be best for the voters.

"Public service is the most noble cause," said Boucher. "I guess those in the ministry might challenge that assertion, but I certainly believe that it's true."