Peter F. O'Malley, a Prince George's County lawyer, is by all accounts a prime mover in the country's recently announced plans to build a $35 million convertion center complex.

The intricate financing arrangement - involving both private funds, state funds and a small operating subsidy from the county - was inspired by O'Malley, according to numerous sources.

O'Malley also helped negotiate the arrangement with county officials.

And at the same time, he is the lawyer for the developer of the project, William J. Levitt Jr., and for the proposed center's next door neighbor, the Capitol Centre, which would benefit financially from it.

It is an almost classic illustration of the degree to which the lines between business and politics have become blurred in Prince's George's County O'Malley is also an unofficial leader of the county's reigning Democratic organization, which holds nearly every important elective office and to which most of the county's General Assembly members belong.

Those delegates and senators in Annapolis will be instrumental in seeking to obtain passage of a $20 million state bond issue to help finance the center in Largo.

The most powerful single member of that delegation, State Senate President Steny H. Hoyer (D-Prince George's) is perhaps O'Malley closest personal friend and political ally.

O'Malley also sits on the 12-member board of directors of an exclusive ($2,0000 a year membership fee) club known as the Council of Economic Progess. The group's main purpose is to push for a convention center in Prince George's County. The group met yesterday, with O'Malley present, to vote formal support for the O'Malley proposal.

It also decided to hire Henry R. Lord, a Baltimore lawyer who recently left his post as deputy attorney general of Maryland, to lobby for the passage of the bond legislation.

"A few weeks ago, O'Malley said that although the county was not inviting proposals (for a convention center), he wanted to submit one anyway," said W. C. Dutton, Jr., chairman of the Prince George's Planning Board and the man designated by County Executive Winfield M. Kelly, Jr., to coordinate the county's end of the project.

The proposal unveiled this week calls for a $35 million convention center, a 600-room hotel, office building and a shopping center on 282 acres near the Capital Centre sports arena, which O'Malley's client Abe Pollin owns and operates.

Developer William Levitt Jr., whom O'Malley represents, would donate the land to the county, which would in turn lease it back to Levitt, who would operate the center.

Assuming legislative approval, the construction would be financed with the $20 million state money and about $13 million from Levitt. Prince George's County would provide a $1.5 million annual operating subsidy.

O'Malley's role spans both the private and governmental aspects of the arrangement. Prince George's officials believe that, nevertheless, they got a good deal. The revenues to the county from a proposed increase in the hotel tax from 5 to 10 per cent, and other revenue from the complex, will more than offset the funds the county would provide Levitt to operate the center, Kelly and his aides maintain.

William W. Beckett, a former president of the Prince George's Chamber of Commerce who is chairman of the exclusive Council of Economic Progress, said the idea of a convention center in the county "looked pretty hopeless until Pete (O'Malley) came up with this proposal . . . I knew Pete had an interest in this location. He was doing this entirely on his own."

O'Malley did not return reporters phone calls yesterday. He has expressed the view to associates recently that he did not feel he recieved fair treatment from The Washington Post.

The council, Beckett said, "would disdain any effort to do anything for a member, but exists for a general benefit to the county."

The council was formed last July. Last fall it gave the county $10,000 for a site and economic study of the convention center. The Levitt property was one of 26 sites listed, but no recommendation was made in the report.

In December County Executive Winfield M. Kelly Jr., a convention center supporter, announced that no more money would be available for additional studies because of general governmental budget problems. This appeared to dim hopes for the project for the foreseeable future.

"Peter's client has owned the land for many years," said Beckett. "The convention center appeared promising, but convention centers are inherently losers, so the overall effort I tried to address myself to is how to come up with sources of funds that would deplete county revenues that were not generated by the center. O'Malley did find a way to demonstrate this could be done."

Capital Center owner Pollin said yesterday he was he has had only passing conversations with O'Malley about the convention center project and has no direct and little indirect interest in it.

"Pollin has recognized there could be some fringe benefits to the Capital Center from having the convention center nearby," said Becknett. "For example, convention families might go to a family-type event like the circus or the Icecapades. Also, the centre could be used for overflow from a very little convention."

In an interview yesterday, Pollin said he thought the Capital Centre would benefit from a convention center anywhere in the "metropolitan area." He said he preferred the Prince George's County arrangement because it involved less money than a proposal to build a convention center in the District of Columbia and less government money.

O'Malley's role in the convention center project is not unlike his instrumental role in getting the Capital Centre built in 1973.

Another nearby property owner is Albert Turner, who built the Kettering shopping center and residential development nearby. Like O'Malley, Turner is a member of the Council of Economic Progress. O'Malley has also represented Turner's Carrollton Enterprises.