More than $25 million in grants and loans will be made available to New York City businessmen who suffered losses in last week's blackout and subsequent rampage of looting, according to federal and city officials.

New York City Mayor Abraham Beame said the Economic Development Administration, the Labor Department, the Law Enforcement Assistance Adminstration and the Small Business Administration will be the major sources of the funds. The city itself contributed $1 million to a rescue fund established to provide grants from $250 to $5,000 to affected businesses. Major banks, unions and corporations have already pledged another $1.25 million to the fund.

The U.S. Economic Development Administration provided an initial grant of $1 million and indicated that "several million dollars" more would be made available form its budget, the Mayor's office said. The initial grant will be used to identity problems and recovery proposals, while the balance will be used to replace publice facilities and demolish gutted buildings.

To hire workers for emergency cleanup operations, the Labor Department is expected to provide money under the Comprehensive Employment and Training Act.

The Small Businss Administration opened eight crisis centers in the city's five boroughs to handle applications for both home and business loans to those who lost goods in the power failure or whose property was destroyed by vandals. More than 1,500 applications were issued in the first three days of the program.

President Carter's refusal to declare the city a disaster area reduced its access to emergency grants and some loan programs, triggering angered responses from New York's Congressional delegation and city officials.

But Mayor Beame's refusal to label the looting a riot disturbed many businessmen, who said their fire and casualty insurance would not cover their losses unless the incident was an official riot.

Insurance adjusters estimated that the insured losses alone totaled $30 million, according to the American Insurance Association, but the uninsured losses could run close to $1 billion.

Roughly 2,000 small businesses in high crime area suffered most of the damage from fires, looting and vandalism.

The AIS said private insurance companies, the New York Property Insurance Underwriting Association, which administraters the Fair Access to Insurance Requirement plan in New York and the federal Crime Insurance program have agreed to pay on the losses.