Much to the relief of area fishermen, a federal judge Thursday reversed an earlier ruling that cut the number of days fishermen could spend at sea and put several new areas off-limits to them.

Instead, U.S. District Court Judge Gladys Kessler said a compromise plan accepted by most of the parties to the lawsuit before her provided a better means for protecting groundfish stocks while minimizing the economic impact on New England’s fishermen. That plan also reduced days at sea, but to a lesser extent, and put fewer areas off-limits to fishing.

“This is very good news,” said Craig Pendleton, a fisherman from Portland and director of the Northwest Atlantic Marine Alliance, which represents fishermen from Rhode Island to Canada. “It brings us back to a place where there was a lot more agreement, despite the pains and sacrifices it would have involved.”

Pendleton, who owns a 54-foot boat, said there still would be economic hardships under the compromise plan but they would be less than those that would have resulted from the judge’s earlier ruling.

Since Kessler’s April 26 decision, fishermen from Rhode Island to Maine have held protests saying her ruling would put many of them out of business. One was held in South Portland last weekend.

Members of Congress from the region, including Maine’s four-member delegation, have called for federal assistance for fishermen harmed by the ruling. The Senate Appropriations Committee on Wednesday approved $16 million in federal assistance for New England’s groundfish fishermen, $2 million of which is expected to come to Maine. The funding still must be approved by the Senate.

Despite the judge’s change of heart, the funding still is needed, said Sen. Olympia Snowe.

“This is very good news and offers a reprieve from the overly burdensome ruling, but there will still be considerable hardship in the fishery,” the Maine Republican said Thursday.

Conservation groups were upset by the reversal and are considering appealing the judge’s latest ruling, which goes into effect immediately.

“We’re disappointed,” said Geoff Smith, the New England fish conservation manager for the Ocean Conservancy in Portland. “Reductions in fishing effort and area closures are needed to reduce fish mortality.”

The lawsuit was filed in 2000 by four conservation groups that charged that the National Marine Fisheries Service was not doing enough to stop the overharvesting of groundfish stocks such as cod, flounder and haddock. Kessler agreed with the groups and required the parties to come up with solutions. One was hammered out by fishermen’s groups, state and federal officials and one conservation group after five days of mediation. It called for a 20 percent reduction in days at sea, expanded no-fishing zones and required gear modifications to let young fish escape.

Although fishermen said the compromise plan still was hard to swallow, it was better than the 50 percent reduction in days at sea and broader closures proposed by the NMFS and the quotas that conservation groups wanted.

“We continue to believe that [the compromise agreement] is the right interim set of measures,” said Peter Shelley, vice president of the Conservation Law Foundation in Rockland. The CLF was the lead plaintiff in the lawsuit but later joined forces with fishermen and government officials because it realized that stringent regulations called for by other conservation groups would harm fishermen.

The judge’s initial ruling would have created “manifest injustice,” Shelley said, and he praised her for reviewing her decision in light of requests to do so from most of those involved in the lawsuit.

Because most groundfish stocks are rebounding, stringent measures that would harm fishermen greatly were not needed, Shelley said.

“This is good news for Maine,” he said. “People are still going to suffer but they will suffer less than under the [original] court order.”

While Kessler adopted much of the compromise plan in her initial ruling, she added new off-limit areas and was more restrictive in calculating the number of days fishermen could spend at sea, costing some 10 days on the water. These changes are what fishermen, state and federal officials and the CLF objected to when they asked the judge to reconsider her action.

In the order vacating her April ruling, Kessler wrote Thursday that she had come to realize that her decision “would produce unintended consequences.” Among them would be to “cause grave economic and social hardship, as well as injustice to individuals, to families, to fishing communities, and to surrounding cities and states,” she wrote.

Smith of the Ocean Conservancy acknowledged the April ruling would have caused some hardship but said the judge should have stuck to her guns.

“The order would cause short-term economic hardships, but those hardships are necessary in the short term to rebuild stocks,” he said.