The Metro financial proposals made public yesterday are the second part of a two-step exercise local governments and the Metro board have been going through to meet federal requirements.

The first part started in November 1976 when Metro was directed by the federal Urban Mass Transportation Administration (UMTA) to restudy uncompleted Metro lines and determine whether the subway was the best way to solve transportation problems in the areas served by those lines.

That study, completed last spring by a regional task force of politicians and technicians, resulted in a finding that Metro's subway was, indeed, cost-effective. The task force recommended that the 100-mile system originally planned for Metro in 1968 by completed, with some modifications.

The second step was a rejuirement from Transportation Secretary Brock Adams that Metro propose solutions to its considerable financial problems before additional federal money would be released to help build the system. Specifically, Adams said he wanted Metro's plans for:

Retiring $1 billion in revenue bonds.

Paying for the annual operating deficits of the combined Metro bus and subway system.

Financing the costs of building Metro beyong the 60 miles already funded and under construction.

Adams also insisted that Metro establish priorities for its uncompleted subway lines and hat its construction schedule include a proposal that would cut off Metro construction at about $5 billion. Under the best estimates available, that would have given Metro somewhere between 70 and 80 miles of operating subway.

Following is a summary of the Metro plan to meet Adams' requirements, plus Adams' initial response on each point, if any, at his press conference yesterday.Revenue Bonds

Metro is proposing that the $1 billion revenue bonds be retired by a combination of federal and Metro money in a ratio of 80 percent federal, 20 percent Metro. Adams said that the federal government is proposing a 50-50 split, but what "we are willing to negotiate a new agreement with Metro."

The federal government has guaranteed the bonds, which were supposed to be paid and retired with excess Metro fares. Operating Deficits

Metro is assuming that with the subway completed in 1990, its total bus and rail operating deficit will be about $328.6 million annually - or more than three times the current deficit in inflated dollars.

There is an existing nationwide federal program that provides about 20 per cent of Metro's operating deficit. Metro assumes that program will continue. The rest of Metro's deficit is paid by various local and state tax sources, especially the property tax.

Metro is proposing that each of Metro's major partners - Maryland, Virginia and D.C. - adopt a tax dedicated to Metro operating costs. Sales taxes, payroll taxes, income tax surcharges, parking taxes and other special levies all are suggested as options. Adams said he believes that dedicated tax revenue for operating costs is essential to guarantee the future of the system and federal participation in it.

Metro's plan also assumes that the federal government will start charging its employes market rates for parking and transfer that money to Metro - a favorite annual proposal of the District of Columbia that never goes anywhere. Adams said he did not think it would go anywhere this time, either. Construction Costs

Sixty miles of Metro is approved and funded and another four miles is partly funded and under construction. The total bill for that 64 miles is about $3.7 billion. Metro offered two plans yesterday to complete the other 36 miles.

Plan I, Metro's preferred plan, would cost a total of $6.7 billion and would result in completion of the 100-mile system late in 1985 with a heavy funding effort peaking in 1981. About half the $2.4 billion in federal money needed would come from interstate highway transfers; the rest from direct appropriation. State and local governments would have to raise $600,000.

Under Plan II, the total system cost would be $6.9 billion and completion would come in 1987 under a stretched construction schedule with more equal annual funding levels. The extra cost is due to the extra time.

Plan II would be divided into two tiers in an attmept to meet Adams' requirements for priorities and a $5 billion ceiling. In the first tier of about $1.5 billion, Metro would:

Acquire all the land and complete the design for the 100-mile system.

Complete the Mid-City line from Anacostia to Gallery Place, the Vienna route from Ballston to Vienna, the Potomac River crossing between the Pentagon and L'Enfant Plaza and the Franconia route from King Street to Van Dorn Street.

Start structural work between Silver Spring and Wheaton on the Glenmont line and between Fort Totten and Prince George's Plaza on the Greenbelt line.

The 100-mile system would be completed in Tier II.

Adams said he preferred the second plan, with its lower annual funding levels. He also said federal funds should come from interstate highway transfers and that new segments should be "usable and contiguous." There will be negotiation on what "usable and contiguous means, particularly with reference to the Glenmont and Greenbelt line extensions.

Adams said he would oppose direct appropriations for Metro because "we don't think such a bill can carry." He proposed that federal money beyond the interstate transfers should come from existing federal programs for aid to mass transit projects nationally.