UnitedHealthcare of New England’s profits climbed by double digits between 2004 and 2007 even as its membership declined, according to a new report by a national nonprofit group.

The report, “Insuring Health or Ensuring Profit?” by the Northwest Federation of Community Organizations, examines recent financial trends for major national health insurers — including Rhode Island’s two major private insurers — as well as their subsidiaries and independent insurers in 26 states, including Rhode Island.

The report’s findings were highlighted yesterday by Ocean State Action and the state arm of the national advocacy coalition Health Care for America NOW during a rally in front of UnitedHealthcare’s offices on Kilvert Street in Warwick. The report shows how the insurance industry’s “skyrocketing profits” are being “skimmed” from health insurance premiums paid by consumers, according to a statement released by Ocean State Action.

UnitedHealthcare of New England has nearly 1 million members in six New England states, including 230,000 in Rhode Island. Its rival, Blue Cross & Blue Shield of Rhode Island, had about 578,000 members in the state as of June 30.

UnitedHealthcare of New England is a subsidiary of UnitedHealth Group, one of the country’s major insurers.

The report by the Seattle, Wash.-based nonprofit group examines how the rise in profits at various health insurers compares with their growth — or decline — in membership. It also provides a ratio of profits “per member, per month” as a way to compare insurers that have different size memberships.

In Rhode Island, Blue Cross reported a far greater increase in profits than UnitedHealthcare of New England — up 330.7 percent during the three years — while its membership increased by 42.3 percent, the report said.

By contrast, UnitedHealthcare of New England’s profits during the same three years rose by 86.7 percent, the report said, but its membership declined by 30.5 percent.

“It raises the question as to why [UnitedHealthcare’s] financial health is improving when they’re providing insurance to fewer people,” said Julie Chinitz, a staff attorney and researcher at the Northwest Federation of Community Organizations.

UnitedHealthcare of New England’s “per member, per month” profit last year was $19.85 — more than twice the $9.99 for Blue Cross, the report said.

(The organizers of yesterday’s rally chose to focus their protest on UnitedHealthcare “because as a for-profit [insurer] there is a much clearer, more transparent stream of dollars drained out of our health-care system and into profits,” Ocean State Action spokeswoman Victoria Picinich explained in an e-mail.)

The insurer with highest per month, per member profit of those examined in the report was $81.31 at PacifiCare of Texas in 2007. PacifiCare is a subsidiary of UnitedHealth Group.

UnitedHealthcare New England’s spokeswoman, Debora M. Spano, declined to comment on specifics in the report, saying she did not know the source data or methodology. (Both are described in the report, which is available at www.nwfco.org)

“We do recognize the need for an appropriate balance between providing services to our members, reinvesting for the future and solvency,” Spano said in an e-mail. An analysis of this issue was conducted last year by the Office of the Health Insurance Commissioner. “We agree that level of diligence applied by OHIC is necessary,” she stated, “to determine what is appropriate for Rhode Island.”

A spokesman for Blue Cross limited his response to the report to the findings on “surplus and capital,” which in the case of Blue Cross rose nearly 50 percent in four years, from $286.5 million to $428.8 million. (United’s rose 35.7 percent, to $119.3 million, the report said.)

“As a local nonprofit company, any excess revenue is added to our reserves,” Blue Cross spokesman Christopher J. Medici stated in an e-mail. “Our reserves are for the protection of our members.”

A recent study by the Office of the Health Insurance Commissioner recommended that Blue Cross maintain reserves of “between 23 and 31 percent of total revenue,” Medici said. “Currently, we are operating at the low end of that range.”

He declined to further comment “until we carefully review the report.”

larditi@projo.com