At Peat Marwick, Mitchell & Co., a senior partner in the Washington office had a new job yesterday - gathering information for dissemination to branches of the big accounting firm across the country, and to corporate clients, about the government's new anti-inflation program.

A few blocks away, at the law offices of Jones, Day, Reavis & Pogue, attorney Philip A. Fleming was resuming a task he performed when the Nixon administration established wage and price controls seven years earlier. He answered calls from business clients about the Carter administration campaign and worked on assembling a team of three or four lawyers to handle the business.

Telephones lines also were busy at the headquarters of the Association of American Railroads, a major trade group. Presidents of individual rail corporates wanted to know, for example, if their current depressed profitability (losses in many cases) have to be maintained under guidelines that restrict growth in earnings.

Thus began what many professionals believe may be another spurt in business activity for an already growing sector of the local economy - providing such services as advice and counsel to business throughout the country.

Even if the administration is successful in its goal of reducing government payrolls by attrition, the number of jobs lost in the metropolitan area probably will be more than balanced by new employment in the private business of figuring out what government wants.

That means more work for lawyers, accountants, trade association executives and lobbyists or Washington affairs positions with major corporations.

"Company people want to be sure they operate on the basis of the latest available information, from someone else in their own firm, from a trade association, a Washington lawyer . . . or some other guy in the business to provide a basis of comparison," said lawyer Fleming.

In particular, companies that have government contracts are concerned about what types of procedures will be used to monitor compliance with the Carter guidelines, he added.

To handle such business, the Jones, Day firm has "resurrected an alumni group" of lawyers who worked for clients on the Nixon controls, "not all of whom are keen . . . and there will be one or two younger ones who can approach this with the eagerness of youth," he added.

Stephen Harlan, of the Peat Marwick office here, said yesterday that his accounting firm had to detach a top partner for the anti-inflation program because senior officers of client corporations are the ones seeking information. "That has the effect of adding people," Harlan said, to handle existing business.

Currently, there are 26,000 lawyers, 25,000 accountants and more than 40,000 professional or trade association workers in the metropolitan area. In addition, the law and accounting firms employ more than 10,000 clerical and other workers for a grand total labor force that numbers about 1.5 million.

Jobs in all three sectors increased sharply in the early 1970s, as government established a new role in monitoring the national economy. For trade associations, in particular, Washington became a boom town and surpassed Chicago and New York as the largest center for such organizations.

Robert Linowes, a lawyer who also is president of the Metropolitan Washington Board of Trade, forecast yesterday that the Carter administration program will accelerate the opening of branch offices here by major law firms based in other cities.

"I'm really not sure how effective it will," he said of the program itself. "But it will increase the number of law firms and bring more competitive activity" to his profession, Linowes added.

At least 50 law firms have been planning Washington offices and the new economic program will accelerate that activity, another attorney forecast.

Thousands of other Washington businesses also will be affected by the new program, of course, but officers interviewed yesterday said they doubted it would add jobs. People will be detached for accounting activities an doutside lawyers; accountants and association executives will be consulted.

Waldo Burnside, president of the Woodward & Lothrop department store company, said yesterday that he had talked already with personnel officers in an effort to begin gathering data on wages. Research people on the Woodies staff are gathering details on the Carter program,and merchandise managers, buyers and financial officers will be brought into a company-wide effort to understand and comply with the requirements he said.

"We're at the mercy of raw materials people . . . our people at the Paris showings have told us of some high numbers (prices) for new fashion imports," Burnside said.

From the Bethesda headquarters suite at Martin Marietta Corp., meanwhile, President Thomas Pownall dispatched a message to all managers throughout the country. "Martin Marietta' intent is to comply fully with the spirit and letter" of the guidelines, it said.

But a spokesman noted that the message was only the beginning effort by the area's largest industrial corporation. "We're trying to find out what it all means, it will take some time of lawyers, accountants . . . and we hope it will work," said Vice President Roy Calvin.

And on L Street in downtown Washington, Cousteau's restaurant placed a blackboard on the sidewalk with a message for the day: "Inflation, recession, wage-price controls, rebates - it all sounds pretty depressing to me." The special for the day, incidentally was lasagna and tossed salad - for $4.50.

In Norfolk, meantime, Virginia Democrat Andrew P. Miller, a frequent critic of the Carter administration, praised the president's new wage and price guidelines as a "significant step" in the nation's continuing battle with inflation.

"Obviously there's not going to be total agreement on all the provisions. . . "Miller told the Norfolk Chamber of Commerce in a joint appearance with his U.S. senatorial opponent, Republican John Warner. "But the point is that at last we're moving . . . to develop a national consensus where management and labor can work together. . ."

Miller singled out for particular praise Carter's proposals for a partial freeze on federal hiring, a review of federal regulations to determine their cost effectiveness, and efforts to reduce both the federal deficit and the federal government's input into the nation's economy.

Warner said, "Of course we'll watch the president's move here . . ." but said he thought Carter was wrong to oppose further tax cuts.

"The free enterprise system needs a good shot in the arm," he told the Norfolk businessmen. "That system can help America get itself up out of inflation." He called particularly for an "across-the-board tax reduction for small business" and said "we've got to watch the impact on the free enterprise system" of the president's wage and guideline proposal.