In a step that left the lawyer for Vice President Bush's political action committee (PAC) "very pleased," the Federal Election Commission yesterday moved toward giving a green light to the PAC to participate in precinct delegate elections in Michigan this summer.

The elections are the first round of a three-stage process that will culminate in the selection of Michigan's delegates to the 1988 Republican National Convention, and are widely viewed as the opening contest of the fight for the GOP presidential nomination.

The PAC, called the Fund for America's Future, has a staff of four full-time and nine part-time employes in Michigan recruiting party activists to run for the more than 10,000 precinct delegate slots. It is planning to spend more than $100,000 on the campaign.

Earlier this week, the FEC legal staff issued a draft opinion that held that any money the PAC spends to recruit candidates, disseminate information or make donations to delegate candidates must be treated as a presidential campaign contribution, subject to an overall $5,000 limit for the PAC.

Yesterday, however, only one of the six members of the FEC, Democrat Thomas E. Harris, was ready to accept the draft opinion.

The other five members of the bipartisan commission were divided between those who thought that such expenditures were subject to no limits, and those who believed that, while they should not be subject to the $5,000 PAC spending limit, should be retroactively counted against overall and state-by-state spending limitations for a presidential candidate if and when Bush formally declares.

The staff was asked to draft opinions covering both approaches, and resubmit them to the commission for action next week.

During the two-hour discussion yesterday, Republican Commissioner Thomas J. Josefiak argued that the delegates running this summer in Michigan will not be identified on the ballot as to the prospective presidential candidate they support, and that therefore the elections are primarily exercises in party building, not presidential politicking. The other two Republicans on the commission, Chairman Joan D. Aikens and Commissioner Lee Ann Elliott, supported his remarks.

Democrat John Warren McGarry argued thast because the delegates are the closed universe of electors who will pick Michigan's national convention delegates, the precinct elections are "inextricably intertwined" with presidential politics.