In 1978, the Chicago Board of Trade Clearing Corp. was looking for Washington attorneys to help its lobbying effort on the first authorization bill for the Commodity Futures Trading Commission.

One of those hired was Christopher R. (Kip) O'Neill, a 1976 graduate of Georgetown Law School and the youngest son of House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.).

"We had members of the board of governors that had known him for years . . . and had known his father for years," said Walter Brinkman, president of the corporation. "That's the reason we hired Kip to do this."

Today, O'Neill & Haase, the law firm headed by the 32-year-old son of the speaker of the House, is among the fastest-growing lobbying operations in this city. It resembles in its early stages the firm of Patten, Blow, & Boggs, in which the Boggs is Thomas Hale Boggs Jr., son of the late House majority leader.

Young O'Neill's firm currently is registered on Capitol Hill for 16 clients, ranging from major corporations such as Westinghouse and Western Union, to special-interest groups like the Glass Packaging Institute, to government bodies such as Alleghany County, Pa.

Twelve more clients are listed as "inactive" in the lobbying reports on file with the Clerk of the House, including Texas Oil & Gas Corp., Motorola Inc., and Premier, the short-lived cable motion picture firm organized by Getty Oil and four movie studios.

One of its newest clients, the Marriott Corp., is known for its strong ties to Republicans. Marriott signed up with O'Neill early last month to seek a change in a new provision of the tax bill.

In the tax increase bill they approved early yesterday morning, the House-Senate conferees have accepted the provision Marriott supported. If Congress passes it, it could save the Washington-based company $55 million, estimates one congressional tax specialist.

The younger O'Neill, since early 1981, also has served as legal counsel to the Democratic Congressional Campaign Committee, the fund-raising and fund-dispensing group. For that, his firm receives a $2,000-a-month retainer plus time charges. As of June, the committee owed the O'Neill firm $36,000, according to reports filed with the Federal Election Commission. The bulk of that debt was attributed to work on a case brought by the National Conservative Politial Action Committee.

The younger O'Neill was unavailable for comment last week.

His father made it clear in a telephone interview last week that he was in no way connected with his son's business.

"My son is a functioning lawyer," the speaker said. "We never discuss legislation . . . . I don't know who his clients are . . . . My son would never embarrass me and I would never do anything to embarrass the exalted position I hold . . . . I had nothing to do with his being hired by the campaign committee . . . . I don't even know if he is paid . . . . No man can say I ever asked them to do one favor in hiring Kip . . . I have too much respect for the job and for my family."

One associate of young O'Neill's firm is Andrew Athy Jr., a Massachusetts family friend. His sister, Susan Athy, is a legislative assistant in the speaker's congressional office.

One contemporary of Kip said last week he was considered "friendly and a hard worker" but one who had "a lot of good contacts."

The wealth of the younger O'Neill's connections was illustrated by his activities on behalf of Marriott.

On July 26, a letter signed "Kip O'Neill" was sent to Rep. Dan Rostenkowski (D-Ill.), chairman of the tax-writing House Ways and Means Committee. Rostenkowski is also vice chairman of the congressional campaign committee.

In his letter, O'Neill said the Senate Finance Committee-adopted provision, which called for corporations to capitalize rather than deduct as business expenses the interest and taxes for construction, was "simply bad tax policy."

When the bill reached the Senate floor, however, an amendment was introduced by Sen. Orrin G. Hatch (R-Utah) that exempted from those provisions corporations building hotels and motels where construction begins before Jan. 1, 1984, but for which approval had been sought from a governmental agency before July 1, 1982.

"That description was drawn up to fit Marriott," according to one member of the Ways and Means Committee who subsequently was approached on the measure by Kip O'Neill.

When the tax bill went to the House-Senate conference, Kip O'Neill telephoned or personally spoke to several members about supporting the Hatch amendment.

When the House members of the conference committee voted on the Hatch amendment, it won 4 to 3. Rostenkowski, said one of those present, was among those voting aye.

Barry L. Haase, one of the other senior partners in the O'Neill firm, is a former director of pipeline and producer regulation for the Federal Energy Regulatory Commission. The other senior partner, Rex Harding White Jr., runs the Austin, Tex., office of the firm.

From 1976 to 1979, White was general counsel to the Railroad Commission of Texas, the group that, despite its name, controls oil drilling in that state.

Thus three senior partners bring together an expertise in regulation, energy production, and lobbying. Their client list, as reflected in lobbying reports filed on Capitol Hill, shows companies with interests in all three areas. For example, the Houston Natural Gas Corp. has hired the firm to follow the coal slurry pipeline bill. Panhandle Producing Co., of San Antonio, Tex., employed it for up to eight months to work for repeal or modification of sections of the Natural Gas Policy Act. Texas Utilities Services Inc., of Dallas, has the firm, according to its report, on an "indefinite" retainer to follow "national energy policy."