Catholic Medical Center on the West Side of Manchester.

MANCHESTER — More and more New Hampshire hospitals are finding dance partners.

Two major proposed deals announced last week further tightened the relationships among the state’s 26 acute-care hospitals, which are looking for ways to control costs, expand services and keep more patients from going to out-of-state hospitals.

“Over the past six years, including proposed transactions, more than half of the hospitals have had some type of transaction that we’ve had to review,” said Tom Donovan, director of the state’s charitable trusts unit in the Attorney General’s office.

Transactions that call for a change of at least 25 percent of the voting control of the board of directors or the formation of a new parent organization that would control them would require a review by the charitable trusts unit, he said.

By his count, only six of the 26 hospitals “are not part of a formal controlled network,” Donovan said. Those are Concord Hospital, Lakes Region General Hospital in Laconia, Speare Memorial Hospital in Plymouth, Cottage Hospital in Woodsville, Valley Regional Hospital in Claremont and Exeter Hospital.

And that could soon drop to five — if Exeter works out details to join a new network.

“Exeter Health Resources, Massachusetts General Hospital, and Wentworth-Douglass Hospital signed a letter of intent last May to explore opportunities to develop a new regional network to collaboratively deliver health care within the Seacoast region,” said Debra Vasapolli, director of public relations at Exeter Health Resources.

“A new regional nonprofit corporation will be developed that serves as the parent to Exeter Health Resources and Wentworth-Douglass, and the new corporation will be a subsidiary of Mass. General.” she said. “As part of the process, the organizations will look at ways to support a shared vision of strengthening, enhancing and growing clinical programs and services to best meet the health care needs of the Seacoast community, while providing care in a cost-effective, coordinated and sustainable manner.”

Last week, Frisbie Memorial Hospital in Rochester announced it will join the for-profit HCA Healthcare network.

And Dartmouth-Hitchcock Health and GraniteOne Health said they want to combine forces.

D-H Health includes Dartmouth-Hitchcock Medical Center in Lebanon, New London Hospital, Cheshire Medical Center in Keene and Alice Peck Day Memorial Hospital in Lebanon.

GraniteOne Health includes three hospitals: Catholic Medical Center in Manchester, Huggins Hospital in Wolfeboro and Monadnock Community Hospital in Peterborough.

Norris Cotton Cancer Center

Dartmouth-Hitchcock’s Norris Cotton Cancer Center has been a presence for years at Catholic Medical Center in Manchester. D-H and CMC’s parent, GraniteOne, announced plans for a more extensive alliance last week.

“I think the important thing is not so much to get big but to get better at what we do,” said CMC’s CEO Dr. Joseph Pepe, who also is the chief executive of GraniteOne.

With all the proposed deals pending, “the AG will be busy,” said Dartmouth-Hitchcock Health CEO Dr. Joanne Conroy during an interview last week.

What’s propelling this?

“It is clear that hospitals and health systems in New Hampshire are working with a variety of other hospitals, stakeholders, insurers and others to reshape the health-care landscape by striving to become even more integrated, aligned, efficient and accessible to the patients and communities they serve,” said Steve Ahnen, president of the New Hampshire Hospital Association.

Pepe said the industry is facing changes.

“In one way, it’s a coincidence,” he said, but economic pressures and increased regulations and how hospitals are paid are also resulting in more partnering.

“But from our point of view, we’re being very proactive and we’re in strong positions, so that’s why we want to take this opportunity to come together.”

Conroy said stronger ties were needed to achieve more.

“We’ve been collaborating for 10 to 15 years and we already have programs that we share on the CMC campus, but if you don’t actually come together under one entity, there are limits on how much you can actually collaborate and integrate. The downward pressure on prices does speak to how much you can integrate, so you can actually control your cost growth,” she said.

“We have much better buying power as you get bigger” when it comes to pharmacy prices, Conroy said.

Pepe said hospital deals, including his own, will need to undergo antitrust scrutiny. Despite the consolidation within the state, “there’s so much other competition out there,” he said.

Donovan said his office has 120 days to review hospital deals.

“We’re the backstop to see whether the boards of director have properly considered the best interests of the hospitals and the communities they serve,” he said.

Pepe’s CMC already has formed relationships with other hospitals, including with Mass. General.

“All the partnerships we have we’re still going to maintain and, in fact, we hope to enhance as a larger organization,” Pepe said.