The preliminary budget Mayor Bloomberg is to unveil today will contain sweeping changes for how arts and cultural institutions are funded, establishing a new, competitive system to distribute money to organizations based on what they are achieving, rather than their connections.

Supporters say the change would more equitably distribute a larger amount of money and end a process critics have called archaic and laden with decades-old favoritism.

Mr. Bloomberg said the current process promotes a system whereby hundreds of cultural groups have to lobby lawmakers and compete for funds.

The new system would allot about $30 million each year to smaller arts groups and open up the funding to almost 1,000 cultural institutions in the city, the administration’s Department of Cultural Affairs predicts.

In addition to the new arts funding system, the mayor and City Council speaker, Christine Quinn, said the parks department and the Administration for Children’s Services would receive a guarantee of minimum funding as well. Parks would receive at least $14 million for enforcement, maintenance, and tree care, and the budget would provide at least $10 million for child care programs.

Ms. Quinn heralded the change as another nail in the coffin of the “budget dance,” in which council members haggle each year with the mayor’s office over funding for the same individual programs that haven’t made it into the permanent budget.

The speaker said the dance has long distracted lawmakers.

“Now I’m very excited about the time we come back in the future and the dance can be totally over and you and I can find some other hobby outside of ballroom dancing,” she said to the mayor.

Under the new system, Mr. Bloomberg said, cultural groups in the city would be able to apply for funds from a pool in a competitive system that the mayor says is based on merit, rather than on an organization’s ability to lobby or be lucky enough to have had its funding locked into the budget decades ago. Arts groups big and small that receive the tens of millions of dollars in arts funding from the city celebrated the announcement.

“No more so-called budget dance,” the manager of government relations for the Metropolitan Museum of Art, Thomas Schuler, said yesterday.

He said the 137-year-old museum welcomed the new budgeting process, which includes a requirement that the 34 institutions that the city owns compete for part of their funding.

“We’ve been doing that for years and years and years, and we have no problem advocating for our needs,” Mr. Schuler said, referring to its accounting procedures.

The city institutions receive will be about $120 million, including $4.4 million to fund new special needs.

Under the mayor’s proposal, about a tenth of the budgets of these 34 intuitions, which include the Met, the Brooklyn Museum, and Carnegie Hall, would be awarded based on objective criteria in a program called “CultureStat,” a program modeled on Police Department’s CompStat program that tracks crime patterns. The criteria include how well they maintain their grounds and accounting.

The Met museum receives almost $27.5 million a year from the city,

Mr. Schuler said. Several of the institutions that receive far less in city funding also welcomed the change.

“We’re thrilled. We think it’s a really good thing,” the executive director of Elders Share the Arts, Carolyn Zablotny, said after the mayor’s announcement. “That idea of leveling the playing field — I think it does help, just speaking as the director of a small arts organization.”

Ms. Zablotny’s Brooklyn-based group, which encourages older people to tell their stories through theater, writing, and painting, receives about $7,500 of its close to half-million-dollar budget a year from the city.

Under the proposal, she would no longer have to lobby elected officials as in years past for her modest budget.

The process was “byzantine,” the president of the Alliance for the Arts, Randall Bourscheidt, said.

Mr. Bourscheidt, whose group gets nearly 10% of its budget from the city, said that as a former deputy commissioner of the city’s culture agency decades ago, he has “special admiration” for the changes announced yesterday.

The mayor and the speaker said the new process would mean more time for art and less time for lobbying.

“They can stop all the lobbying and get back to doing what they’re supposed to be doing — making the greatest cultural institutions in the world even greater,” Mr. Bloomberg said.