DENVER, DEC. 21 -- Gary Hart set out to put financial meat on the bones of his skeletal presidential campaign today, banking the first $6,000 of contributions from backers nationwide and formally filing with the Federal Election Commission for matching public funds.

Hart's reborn campaign presented the FEC with an initial list of contributions that would garner $141,285 in matching funds. Meanwhile, Hart volunteers began preparing a much longer list of contributions.

Hart's aides said the campaign could receive about $1.1 million in matching funds next month if the FEC agrees that contributions made before he dropped out of the race in May are eligible for matching funds now that he has returned.

The FEC has not ruled on that question, but Hart's financial advisers have said they expect a positive response.

Sue Casey, de facto campaign manager of the new, phase-two Hart drive, said today that the first bags of incoming mail after Hart's surprise reentry yielded about $6,000 in contributions. She said mail is arriving steadily.

In addition, Casey said, the campaign expects access soon to $100,000 held in a bank account in the name of Hart's 1988 campaign. That has been tied up in a federal court suit here by creditors of Hart's 1984 campaign.

Casey said she expects a legal ruling holding that 1988 money cannot be used to pay the 1984 debt. Such a ruling would free the entire $100,000 for use in Hart's campaign.

Last week, Hart said he would run a bare-bones campaign with "no money, no consultants, no national headquarters."

In fact, his campaign opened a two-room, basement headquarters here last weekend, and Hart is moving fast to establish local organizations in key primary states nationwide.

Casey said the campaign also expects to open a "small office" in Washington and another in New Hampshire. Hart's tentative plans call for him to focus on the New Hampshire primary Feb. 16 in the hope that a strong showing will assure a place among leading Democratic contenders in subsequent primaries and caucuses.

Hart made his only scheduled campaign trip of the week today, traveling in the no-frills style he has promised.

Accompanied by his wife, Lee, and her friend, Linda Spangler, Hart drove a borrowed car from Denver to Cheyenne, Wyo., for two hours of handshaking at a shopping center. He then drove back to Denver and spent the afternoon calling campaign volunteers organizing state-by-state efforts.

Hart met over the weekend with former advisers who have signed on again. They include Eli Segal, the Boston businessman who will oversee fund-raising, and Bill Shore, the Washington consultant who has been Hart's closest political confidant.

One of the key priorities identified by this group is the mechanical job of qualifying Hart and delegates committed to him in states where qualification deadlines are approaching.

In Illinois, for example, Hart has one week to produce enough signed petitions for a spot on the ballot. He dispatched Martin O'Malley, a longtime supporter who lives in Baltimore, to Chicago. Casey said O'Malley was told to get the job done and not expect help from headquarters here.

Hart, who has a debt of about $1 million from his 1984 campaign, has said he is determined to pay what he owes. As is common among presidential candidates, he has worked hard to prevent creditors of his earlier campaign from obtaining money donated for the current effort.

Staff writer Charles R. Babcock contributed to this report.