A federal judge has given a historic $7.25 billion swipe fee settlement his final approval, but a faction of ­retailers has signaled plans to continue fighting.

The huge class-action antitrust settlement, which set a U.S. record, aims to resolve claims that Visa, MasterCard and a group of card-issuing banks colluded to fix the "interchange fees" U.S. merchants must pay when shoppers swipe a MasterCard or Visa card. The fees totaled more than $30 billion last year, and the settlement already has given merchants the freedom to pass the fees on directly to consumers via surcharges, although very few are doing that yet.

At least three appeal notices were immediately filed after U.S. District Judge John Gleeson in Brooklyn, N.Y., blessed the accord on Friday. Home Depot filed one, and another was filed by a group of 21 retailers that includes Minneapolis-based Target Corp. and Macy's Inc.

Also planning to appeal the pact's approval is a large group that includes 10 of the named plaintiffs in the ­lawsuit as well as a long list that includes some of the country's retail royalty, such as Amazon.com Inc., Starbucks Corp. and Wal-Mart Stores Inc.

While expected, the appeal notices underline the depth of division over the pact. They also make it clear that no one will see refund checks for some time.

Appeals filed in the Second U.S. Circuit Court of Appeals can take 15 to 18 months to resolve, according to Craig Wildfang, an attorney for the retailer class. If Gleeson's decision is upheld, that would mean refund checks could go out to retailers in the fall of 2015, he said.

The National Retail Federation issued a statement expressing its disappointment with Gleeson's approval.

"[The settlement] is not supported by the retail industry and would do nothing to reduce swipe fees or keep them from rising in the future," the group said. "The settlement permanently ties the hands of thousands of businesses who wanted nothing to do with this misguided case, and a decision to approve it violates established law and common sense."

The largest antitrust class-action settlement in U.S. history was announced in the summer of 2012 after seven years of litigation over interchange fees, which average about 2 percent of every ­purchase. Last year, merchants paid more than $32 billion in interchange fees on Visa and MasterCard credit and debit card payments, according to the Nilson Report.

The first lawsuit was filed in Minnesota in 2005 by Wildfang, a prominent antitrust ­litigator at Robins, Kaplan Miller & Ciresi in Minneapolis who ultimately quarterbacked the national settlement.

The agreement permits merchants to pass on their interchange fees to card-paying customers via a surcharge, a change now in effect, and requires Visa and MasterCard to negotiate with merchant buying groups, something they have not done before.

It also calls for the defendants to pay cash damages to the more than 7 million affected retailers, although the individual payments will be a small fraction of the total interchange fees the retailers have paid over the years.

One feature critics particularly dislike is that the agreement prevents retailers from suing in the future over identical claims about activity before the settlement.

The estimated $7.25 billion the defendants agreed to pay has shrunk to about $5.7 billion because some retailers opted out of the deal.

Craig Thorvig, head of family-owned grocery stores in Sandstone and Pine City, Minn., said he's frustrated because he doesn't think the deal will ultimately curb high credit card fees, which he estimates reach about $100,000 a year at his Sandstone store.

"In general, as technology improves, the price of that technology decreases," he said. "But with credit card fees, the fees increase."

Surcharging customers is not currently an option, he said. "The problem is Wal-Mart has the market share and if they don't do it, there's no way we can get away with it."

In his 55-page memorandum and order approving the deal Friday, Gleeson said the settlement was "fair, reasonable, and adequate" and "an important step forward."

He chastised some of the most vocal dissenting retailers and trade associations for "vitriol and poor behavior and feigned hysteria."

The sweeping reform of the electronics payments industry that many retailers want is beyond the scope of the litigation, he noted. It ignores that despite its enormous size "this is just an antitrust lawsuit," Gleeson wrote.

Jennifer Bjorhus • 612-673-4683