The Robert W. Woodruff Foundation, Atlanta's largest philanthropy, has emerged as the most probable source of a $200 million bailout for Grady Memorial Hospital.

The identity of the donor has been a tantalizing mystery since last summer, when representatives of the Metro Atlanta Chamber of Commerce announced that an anonymous donor was willing to provide a major amount of money to save the foundering hospital.

"In response to speculation that the Woodruff Foundation is a prospective donor for Grady, I can confirm that we have had informal conversations with Grady's board leadership," foundation President Russ Hardin said Thursday.

"Formal consideration of a grant is still a little premature, but things sure do seem to be moving in the right direction at Grady," he added. "Although the process of governance change has been difficult, it's been gratifying to see the state and the community rally to save Grady."

Speculation has long focused on Woodruff as the donor. Grady officials said the donor will be formally identified in a few weeks. That's when the first $50 million installment is expected to be delivered to Grady. The entire $200 million will be paid out over four years.

Woodruff, with assets of $2.7 billion, is Atlanta's most influential charitable foundation. The donation is expected to help draw other givers to the Grady cause. Grady has fallen deeper and deeper into debt because of rising health care costs, dwindling government aid, a lack of paying customers and years of neglect. It ended last year with a budget deficit of $55 million.

With speculation focusing more and more on Woodruff, Hardin issued a statement earlier Thursday:

"The new Grady governing board represents an extraordinary blend of business and health care experience. As the new board assumes responsibility, Grady is likely to receive widespread support from the community and the state."

Hardin's statement continued: "The Woodruff Foundation certainly expects to receive an appeal for charitable support. We are in contact with the new board leadership, but no formal grant request has been received and no formal commitment has been made."

The $200 million donation has been the fulcrum for transition of management control of the hospital from the Fulton DeKalb Hospital Authority to a nonprofit corporation. The business leaders who brokered the deal made it clear that the donation was contingent on the transition.

The transition took eight months of often contentious negotiations, with much public debate. The new board of the nonprofit Grady Memorial Hospital Corporation was named a week ago and elected its officers Monday.

New board Chairman Pete Correll, who co-chaired a Chamber of Commerce task force that recommended the management change, declined to comment Thursday on the identity of the donor.

The first $50 million will be deposited into an escrow account. The check cannot be cashed until the new nonprofit assumes full control of the hospital, which is expected sometime between May and September.

Some critics of the hospital restructuring charged that the business community used the donation to pressure the hospital board and get its approval of the control shift. These critics, including a group of Grady patients, workers and activists called the Grady Coalition, view the change as a white business takeover of the safety net hospital that will result in cuts in services to the poor.

"Almost everyone that I have spoken to believes or understands that it's the Woodruff Foundation," said state Sen. Vincent Fort (D-Atlanta), who has been a critic of the restructuring.

"One man's community project is another man's hostile takeover," Fort added.

The Woodruff Foundation made some $95 million in grants last year. Established by the late head of the Coca-Cola Co., the foundation supports health care, education, human services, economic development, arts, culture and the environment.

Woodruff's impact on the city is vast. There are the Woodruff Arts Center, Woodruff Park and the Woodruff Library at Atlanta University Center. The Woodruff Foundation has richly supported Emory University School of Medicine, Children's Healthcare of Atlanta and the U.S. Centers for Disease Control and Prevention.

A major Woodruff donation to Grady would strengthen the Woodruff-Emory-Grady relationship. Emory already provides the majority of doctors to Grady.

In 2006, the foundation gave Emory more than a quarter of a billion dollars. The bulk of the $261.5 million gift — at the time, the 10th-largest single donation to a school or scholarship on record — will go to expand and improve the Emory Clinic outpatient facility.