Sen. Edward M. Kennedy (D.-Mass.) intervened at the Whited House to head off the selection of a former law partner of Attorney General Griffin B. Bell as chairman of a new antitrust study commission, sources confirmed yesterday.

Although names of proposed members have not yet been submitted to the President, the sources have confirmed that the proposed selection of John Izard, a partner in the Atlanta firm of King & Spalding, was nipped in the bud by a phone call from Kennedy, Senate Antitrust and Monopoly Subcommittee chairman, to Presidential assistant Hamilton Jordan.

Izard was slated to head a special 15-member commission created by an executive order signed by the President. The commission's six-month mission is to consider and make recommendations on two major topics: how to expedite major antitrust cases and whether current antitrust immunities and exemptions are justified.

Kennedy is said to have told Jordan that the commission chairman should not be so closely identified with the defense bar and that neutral selection would be better. He also made it clear that his support of the commission depended on who its members would be.

Kennedy is not a fan of commission generally. Although he said he wouldn't oppose one when the idea came up during subcommittee hearings on antitrust enforcement last spring, Kennedy noted that he had seen too many commissions whose reports "are all gathering dust back in the stacks."

He also expressed concern that a commission's mandate not be drawn so broad that it would duplicate many of the studies already done by the subcommittee and others and that it could be used as an excuse by others to hold off on legislation or litigation pending the recommendations of the commission.

A broad study of the antitrust laws and their effectiveness has been proposed and pushed in recent years by Sens. Jacob Javits (R-N.Y.) and Charles McC. Mathias (R-Md.).

As it is constituted, the commission will have the more narrowly drawn mandate Kennedy favored. The commission will not focus on a general examination of the antitrust laws but only how to improve the handling of the "large" case, such as the government suits against International Business Machines Corp., American Telephone & Telegraph Co. and the oil industry. Its other study area was described by one source as a "regulatory reform" forcus on those areas of the economy that have in large part been exempted from the antitrust laws by virtue of their government regulation.

The commission's membership will be composed of Assistant Attorney General for antitrust matters, John H. Shenefield. Federal Trade Commission Chairman Michael Pertschuk; a chairman of an independent regulatory agency, expected to be Civil Aeronautics Board Chairman Alfred E. Kahn; three members each from the Senate and the House of Representatives, to be selected by them: a federal district judge, and a five at-large members. A defense attorney, a plaintiff's attorney, a member of a public interest group and an academician are expected to be included in the at large membership.

The original list of proposed commission panelists shown Kennedy, which included Izard's name, was drawn up by the Justice Department. No names have yet been submitted to the President, sources said yesterday. Izard is a former chairman of the American Bar Association's section of antitrust law, which had forwarded some recommendations to the Justice Department.