The Anti-Defamation League of B'nai B'rith yesterday accused the U.S. Chamber of Commerce and the National Association of Manufacturers of spearheading a compaign by "large and respectable firms in the block legislation against the Arab boycott. Anti-boycott measures, defeated in the last Congress by Ford administration maneuvers, were introduced again this week.

As evidence of a "coalition" against the bills, ADL's national chairman, Burton M. Joseph, cited in part newspaper accounts noting the presence of lobbyists for these organizations, as well as Carterpillar Tractor Co., Standard Oil of California, and Bechtel Corp. in the hallways outside a closed conference session last September. The newspaper also noted the presence of ADL and other Jewish groups on the opposite side of the hall.

Both organizations denied yesterday they were involved in a coalition but not that they had opposed the bills. The NAM, representing 13,000 manufacturers, issued a statement saying: "NAM has always opposed boycotts as a matter of policy, (but) NAM has been concerned in the light of comments of our members that prospective changes in the U.S. government boycott regulations might prove to be impossible to implement in a reasonable fashion." It added that NAM will "continue to examine proposals to change boycott regulations in order to seek to present realistic and constructive industry views on the issue."

The Chamber of Commerce said it had "the controversial issue under intensive consideration" and would issue a position paper soon. Meanwhile, a spokesman said only that the cnamber's position bears little resemblance to that attributed to it by the ADL.

In addition, the ADL cited 21 others as participating in the coalition. These included Arab-American organizations, oil companies and manufacturers such as American Cyanamid, Bechtel and Caterpillar Tractor, plus the School of Advanced Studies at John Hopkins University.

Spokesmen for American Cyanamid and Carteroillar said they trade with both Israel and the Arab states, oppose discrimination, but are concerned about any proposed legislation.

Associated General Contractors of America also listed, has estimated the construction industry will lose $200 billion in potential foreign construction revenue and 800,000 jobs over the next five years if Congress passes anti-boycott legislation.

Also accused of spearheading the campaign was the Emergency Committee for American Trade (ECAT), which represents 64 major banks and multinational corporations. W. Michael Blumenthal was listed as a member until he recently resigned his chairmanship of the Bendix Corp. to accept nomination as the next Secretary of the Treasury. At his confirmation hearing Wednesday, Blumenthal declared he was "strongly opposed to these sort of boycotts."

His future boss, President-elect Jimmy Carter, pledged during the second pre-election debate with president Ford to "do everything I can to stop the boycott of American businesses by the Arab countries." He also called the Ford administration's blocking of the last legislation "a disgrace." The ADL says it has received no other commitment from Carter since his election.

The ADL also named a second coalition headed by Fall Employment in America through Trade (FEATT), which it described as "a potpourri of American-Arab organizations and extremists linked to antisemitism." These include "General" Hassan Jeru-Ahmed, who holds that the first Americans to lose jobs if the Arabs withdraw their business will be blacks.

FEATT is still in the formative stages and has not been to raise sufficient funding, according to Donald Baldwin, a government relations consultant who quit the group this week. Others listed by the ADL as FEATT participants were Harry G. Raine, a New York-based lobbyist for the Bendix Corp., and Timothy O'Shea, assistant director of overseas affairs of Wastinghouse.

It also was announced yesterday that the ADL and the Business Roundtable, an organization of the chiefs of 170 major corporations, would meet in Chicago Jan. 28 to try to reach an understanding on boycotts. Irving S. Shapiro, chairman of Du Pont, heads the roundtable.

In a related development, the Commission of Economic Coercion and Discrimination, a private Canadian organization, urged Canada to pass anti-boycott legislation. It said the majority of Canadian export transactions with Arab League nations involved boycott compliance.