By Anemona Hartocollis

Gov. David A. Paterson provided the second cash infusion in a week Sunday to St. Vincent’s Hospital Manhattan in Greenwich Village, but said concessions from unions and physicians would be needed to keep the hospital open.

The governor said Sunday that after “hours of intensive discussions and calls between all parties” the state had agreed to put up $3 million and creditors another $3 million to keep the hospital going temporarily.

It was not clear how long the cash would last, and Mr. Paterson challenged other stakeholders to help as well.

The 160-year-old hospital is $700 million in debt and has stopped accepting new outpatients to its well-known H.I.V. and community health programs because it may be forced to close.

The governor said in a statement that saving St. Vincent’s would require “shared sacrifice,” adding: “We believe this assistance, if combined with assistance from the sponsors, concessions from the unions, management and physicians, cost-cutting actions and aggressive cash management will allow St. Vincent’s Medical Center the time needed to develop short-term and long-term plans for the future.”

The loan came on the heels of an $8 million loan from the state and the hospital’s main creditors, GE Capital and TD Bank, that was announced last Tuesday. The first loan was used for payroll and supplies and was exhausted almost immediately, in part because vendors are now demanding cash in advance or on delivery, hospital officials said.

City Council Speaker Christine C. Quinn, state and federal elected officials, and union leaders have become part of a group working with the governor and the state health department to save the hospital.

But so far, neither the city, the federal government nor the unions have proposed to contribute to the state’s efforts to keep the hospital going until a more permanent solution can be found. A spokeswoman for the hospital workers’ union, Local 1199 of the S.E.I.U., declined to comment Sunday evening.

As a political matter, wage concessions are sometimes more damaging to unions than layoffs, because laid-off workers do not vote in union elections while those whose salaries have been cut do.

Mayor Michael R. Bloomberg has taken a neutral, almost philosophical approach to the hospital’s plight. On Friday, he said in his weekly radio program that he doubted the hospital could stay open longer than six months, but he did not offer any help.

“People want to keep it open; that would be great if you could find a way to do it,” Mr. Bloomberg said. “I will say I find it hard to see how you can do that. You might be able to get it through another six months or something. The governor’s giving them a loan to pay their employees for another month, but unless you can really come up with a business model that works, which is difficult in the best of times for the best of hospitals, it’s a really tough proposition to come up with.”