The Archdiocese of Boston is negotiating an agreement to sell the Caritas Christi Health Care system &endash; including Dorchester's Carney Hospital &endash; to Ascension Health, a national Catholic non-profit provider based in St. Louis, Mo.

The news was greeted with guarded optimism by Carney administrators and elected officials.

Under the agreement, Ascension will assume "sponsorship" of the state's second largest health care system, which in addition to Carney hospital and St. Mary's Women's & Infant Center on Jones Hill, includes St. Elizabeth's Medical Center in Brighton (the Caritas flagship) and hospitals in Brockton, Fall River Methuen, and Norwood. Caritas also runs a variety of other health facilities, including Dorchester's Laboure College on the Carney campus and the St. Mary's Women and Children's Center at the site of the former St. Margaret's hospital. The proposed deal would transfer both of these facilities to Ascension.

Ascension sponsorship could ring familiar at the Carney, which was once owned by the Daughters of Charity, an order of Catholic sisters which co-founded Ascension in 1999.

Carney administrators and elected officials adopted a positive but wait-and-see attitude after the announcement this week, speaking highly of the Ascension system but reserving their endorsements because the impact the sale would have on the Carney &endash; Dorchester's biggest private employer with more than 1,250 jobs &endash; was not clear.

"I think we still have to see how this plays out," said City Council President Maureen Feeney, whose district includes the hospital. "If this is a move that will strengthen the hospital, then obviously I'm very excited. But if it's a situation that in any way diminishes its role as a community hospital that serves people far beyond its own catchment area, that would be very disappointing."

In a statement, Mayor Thomas Menino urged Archdiocese leaders to ensure that Ascension would not scale back service at Carney or St. Elizabeth's.

Selling the Caritas system to another provider was one of several options recommended to the Archdiocese by Chicago-based Navigant Consulting Inc., and Ascension was one of three providers considered.

Another option had been to spin off Caritas as an independent entity. James Hunt Jr., president and CEO of the Massachusetts League of Community Health Centers as well as a Carney trustee, said that if Ascension would not commit to investing funds and personnel in Carney, he would recommend the hospital pursue independent management.

"If there is not going to be a capital investment, then I'd rather know that early and try to foster and develop a local partnership with other funders and teaching hospitals," said Hunt. "My hope is that the hospital will be a key priority for investment in capital infrastructure that we need to make the Carney a place of excellence and an attractive partner both for the community and globally."

Administrators and board members from each Caritas hospital were briefed about the deal at a meeting in Waltham on Tuesday night. After the meeting, Dr. Daniel O'Leary, who has served as Carney's president since December 2005, said that he was encouraged by Ascension's strong reputation and mission statement.

"It's clearly a very knowledgeable system that has enjoyed a lot of success," said O'Leary. "They seem very focused on the mission of the underserved and the poor, and subscribe to the same guidelines that Caritas does. I think this could be really very positive for Carney and Dorchester."

This is not the first time that changes at Carney &endash; or changes involving the Daughters of Charity &endash; have created unease in the neighborhood.

Seventeen years ago, the Daughters of Charity owned Carney Hospital and managed the Caritas-owned St. Margaret's hospital in Jones Hill. In 1990, the Archdiocese made a widely unpopular decision to relocate the majority of St. Margaret's services to the St. Elizabeth's Brighton campus, leaving only the St. Mary's Women and Children's Center in place on Jones Hill.

In 1996, the Daughters of Charity sold Carney to Caritas, which recruited Joyce Murphy to serve as Carney's president for the next decade. Murphy brought stability to the Dorchester Ave. campus, but financial strains weighed heavily at Carney, as they have for most hospitals throughout the state. Under Murphy, however, the Carney operated in the black, and developed strong ties with Dorchester's influential legislative delegation, headed by former Speaker Tommy Finneran. Carney is annually among the leading hospitals in the state in providing free care, and the hospital has been successful in recovering much of those costs from the state's free care reimbursement funds. However, the Caritas system's debt load, in excess of $200 million, seems to have contributed to the decision to divest the health care provider.

The well-respected Murphy left as CEO in 2005, prompting concerns that Caritas would decrease programming and support for the Dorchester hospital. Her replacement, Dr. O'Leary, a Dorchester-born research physician who had been a radiologist at New England Medical Center, has assuaged many of those concerns in his 14-month tenure. Currently, under the leadership of Dr. O'Leary and Carney COO Connie Bulman, the hospital has begun implementing a program dubbed "21 points of light," a series of heath initiatives designed to meet local needs while developing new sources of revenues.

Some community leaders this week welcomed the return of a restructured Daughters of Charity health management group.

"Essentially they're back in the game," said Bill Walczak, president and CEO of the Codman Square Health Center. "I thought that by and large they did a really good job. They certainly understand the realities of health care."

Walczak pointed to Ascension's excellent bond rating as evidence that they are also committed to the bottom line, a philosophy that could help the Caritas system overcome its formidable debt.

According to a joint press release from the Archdiocese and Ascension, the deal is scheduled to be finalized in July.