Mayor Marion Barry said yesterday he will support some changes in the city's cable television contract to help the cash-poor District Cablevision Inc. (DCI) build a cable system, but warned that local investors may lose control of the franchise.

District Cablevision disclosed last week that it cannot obtain the necessary financing to live up to the terms of a cable TV franchise agreement that it signed with the city less than four months ago. Company officials asked the city for permission to scale down the system, increase the base rates charged customers and postpone payments owed to the city -- concessions that would be worth $32 million.

"We will make some changes if it means cable is coming," Barry said during his monthly news conference. "Nobody wants to start over with another company and, on the other hand, nobody wants to just say to District Cablevision that because you have these difficulties we are going to do everything you ask us to do."

Barry added that District Cablevision's search for equity investors may bring outsiders into a dominant position in the company.

Denver-based Tele-Communications Inc., the nation's largest owner and operator of cable television systems and a limited partner in the District venture, offered last week to invest at least $30 million to bail out District Cablevision.

"It may come to a situation where DCI will not get the money unless it gives up a significant amount of local control," the mayor said.

On another matter, Barry said he intends to stay out of a dispute between the federal government and the Community for Creative Non-Violence over the fate of a shelter for the homeless at 425 Second St. NW that the federal government is seeking to close.

The White House agreed last year to build a "model" shelter, after CCNV leader Mitch Snyder went on a 51-day hunger strike.

Last week, federal officials announced plans to close the shelter July 10 after failing to reach agreement with Snyder over the scope of the remodeling of the shelter, which is in a federally owned building. U.S. officials said they would give the District government at least $2.7 million to help house the displaced homeless.

Barry said yesterday that the city is "sympathetic to Mr. Snyder's group" and would do what it could to find alternative shelter for the homeless. However, he said, the District is "not going to spend one nickel to renovate the shelter."

In response to a question about reports that Robert Green, the University of the District of Columbia president, had spent over $80,000 in catering costs at his university-owned residence, Barry said that presidents of many universities "are underpaid, generally speaking," and deserve special perquisites beyond their salaries.

City Council member Carol Schwartz (R-At Large) described the expenditures as "appalling" and called for a council Education Committee hearing on the matter.

In discussing the mounting problems with the District's cable television franchise, Barry said that he will send the City Council a letter today or tomorrow proposing modifications in the franchise agreement.

Richard Maulsby, director of the D.C. Office of Cable Television, met Tuesday with Robert L. Johnson, president of District Cablevision, in an attempt to reach agreement on the necessary changes, according to Barry.

The mayor also said he has met with City Council member Betty Ann Kane (D-At Large), head of the Public Services and Cable Television Committee, to iron out differences.

"I think when we send our recommendations over you'll find that she and I are 99.5 percent together on what concessions we have to make," Barry said. "We want cable now."

Barry affirmed his support for a system of "universal wiring" that would assure that cable television is available to every District resident. However, he would not rule out the possibility of a cable blackout in some sections of the city where it would be too costly to install.

However, Kane said yesterday that she would not go along with a proposal to reduce the availability of cable service. "Their request not to wire the entire city is just bottom-line unacceptable," Kane said. "That's against the law governing the franchise agreement . The law has already required that the entire city be wired."

Kane also said that the contract modifications sought by District Cablevision and the investment offered by TCI may not be enough to finance construction of a cable system here.

"We are going to need some guarantees that there really is $30 million and there really are some deep pockets," Kane said.

City officials hope to resolve the problem before the City Council begins its summer recess next month. The council must approve any changes in the franchise contract.