The Inter-American Workers' Organization, which includes among its affiliates the AFL-CIO, ended a two-day session here yesterday with the decision not to go forward with an economic boycott of Chile that has been promised since November.

The decision not to act apparently reflects a conclusion by AFL-CIO President George Meany and three Chilean labor leadors that Chile's military junta has made enough concessions in its fight with unions there to justify suspending the boycott.

Negotiations with the junta began last November, after the affiliates of the hemispheric labor group vowed to refuse all cargoes to and from Chile because of repression by the junta of Chile's once powerful labor unions.

The decision to the boycott cargoes came only after Meany had reluctantly concluded that the junta was attempting to destroy Chile's communist-led unions and affiliates of ORIT, as the Inter-American Workers' Organization is known by its Spanish initials. ORIT is effectively an offshoot of Meany's federation.

Most of the negotiations with the Chilean junta were carried out by Peter Grace, a friend of Meany's who was once a mojor investor in South America and the president of W. R. Grace and Co.

Chile's international trade comes to about $4.5 billion annually, $700 million of it with the United States.

Wenceslao Moreno, the Chilean embassy's labor attache, said yesterday, "The decision was to give Chile time to do what it has promised."

Moreno is a former member of ORIT and an alumnus of another AFL-CIO offshoot, the American Institute for Free Labor Development.

That training center is presided over by Meany with Grace as a chairman of the board and Nelson Rockefeller as a board member. This mixing of labor and management, along with allegations of past CIA manipulation, have made the institute supect among independent Latin unions.

An AFL-CIO spokesman said yesterday that Meany welcomed the role of Grace in the boycott negotiations although he did not represent the union federation. Grace flew twice to Chile in late December.

The junta's decision to replace its hard-line labor minister was at least partly a result of Grace's recommendations, according to Chilean sources. On one of Grace's trips, the businessman gave a ride to New York to Chile's Cardinal Raul Silva, who was receiving an award for his efforts to protect Chileans' human rights.

"The cardinal is another old friend," said a spokesman for Grace, who also insisted that Grace's only interest was to negotiate a solution short of a boycott, which he felt ould be devastating to Chile.

Grace's massive sugar plantation holdings in Peru were nationalized a decade ago and he sold the shipping line that linked Chile to world trade years ago.

The new Chilean labor minister, Jose Pinera, also a friend of Grace, has promised to allow collective bargaining, union dues checkoff and other activities demanded by the unions. However, strikes "against the national interest" are prohibited and some of the other concessions are not to take effect until June.

Union sources are now saying that the threatened boycott is still possible, but, in effect, suspended until June.