Montgomery County Executive James Gleason today broke ranks with neighboring Prince George's County by opposing Prince George's plans to build a $35 million convention center with state and private funds.

Gleason questioned the use of $20 million in state bond money for a project he termed "essentially private enterprise." He also questioned, in the same breath, the involvement of Prince George's County political power Peter F. O'Malley, who designed the convention center proposal for a law client of his.

Testifying before a Maryland legislative committee considering the $20 million request, Gleason said he thought "the issue of close involvement of business and government is important because we have gone through particularly hairy times in this state . . . I don't know Mr. O'Malley personally but I hear he is a political organizer of some high repute.

Gleason is considered a possible Republican candidate for governor in 1978. O'Malley is the campaign manager for Democratic gubernatorial contender, Sen. Steny H. Hoyer (D-Prince George's.)

Gleason compared the Prince George's convention center proposal unfavorably with the District's plans for a $100 million center. "I don't think Largo can really compare with the White House, the Supreme Court and the monuments," he said.

The O'Malley plan call for combining a $20 million bond issue with $13 million from private developer William Levitt, Jr., (an O'Malley client,) to build the center on Levitt's land near the Capital Centre arena. Prince George's County would provide an annual operating subsidy to the center of about $1.5 million, which county official say would be accumulated from new revenues brought in by the center and an accompanying hotel and shopping complex planned by Levitt.

Because Gleason is a Republican and has little control over his county's legislative delegation, his testimony is not expected to be terribly damaging to chances of legislative approval for the $20 million. It did feed already existing skepticism among some members of the House Appropriations Committee, which must approve the money.

Developer Levitt appeared today in support of the project. "I want you to clearly understand the risk entailed for my company," he said, "the risk of (picking up) all cost overruns. My motivation is that the faster this convention center is built, the faster may facilities adjacent to it will be built. That's our only motivation."

O'Malley and county officials have said that the convention center would become possibly the largest single new source of revenue to the county if built and would help hold down or reduce property tax rates there.

Gleason opened his testimony by claiming a "degree of reluctance" in opposing the proposal of his neighboring county, but he then proceeded to tear it down.

He asked why the county could not float its own bonds, why the state should contribute to an "essentially private enterprise" and what guarantee could be offered that the convention center would be a success.

"The convention business is a complicated one, it requires hotel rooms - a lot - it requires exceptional transportation routes and it requires many kinds of attractions because it's the whole family that comes to a convention," Gleason said.

He then ran down the number of rooms available in Prince George's - 1,019 by his count - and compared that unfavorably with Washington hotels.The Sheraton Park alone has 1.200 rooms, he said.

"You compare your plan for a convention outside a city with the Anaheim center but Anaheim, I think is where Disneyland is located," he continued.

On the question of financial success he pointed to the Ocean City Convention Center that he said was such a failure that the state is still required to subsidize its operating costs.

"This proposal does conflict, with our policy of cutting back on debt programs, school construction . . ."

County officials have argued that the District's proposal is both more expensive ($100 million) and involves more government money than the Prince George's proposal.

They also maintain that Largo is close enough to Washington to be able to capitalize on city attractions to draw conventioneers as well as on city hotels.

The District's proposal is expected to be formally submitted to Congress soon. The Prince George's proposal is dependent on action of the Maryland General Assembly, which ends its 1977 session on April 11.