U.S. Justice Department investigates real estate commission's antitrust deal.

The U.S. Department of Justice has expressed "significant concerns" about a proposed settlement in a lawsuit challenging realtors' commissions to realtors for real estate sales.

Attorneys for the Justice Department's antitrust division filed a "statement of interest" in a Massachusetts federal court, saying the deal would not turn around the obligation, but only "tweak" it.

New U.S. courts are hearing lawsuits related to "buyer-realtor commissions" - fees that home sellers must set to get their properties listed for sale nationwide. Critics argue that such rules lead to inflated commissions that violate' 'U.S. antitrust law.

The Justice Department failed to state an objection to an agreement between the plaintiffs - individual home sellers - and one of the defendants, MLS Property Information Network. Attorneys for the plaintiffs said the DOJ failed to be specific about what the possible deficiencies in the proposed agreement were and urged the court to deny the DOJ additional time. The plaintiffs said the proposed agreement "provides substantial equitable relief" for class members.

MLS PIN, known as a "multiple listing service," offers thousands of homes for sale in New England. As part of the settlement, the company agreed to pay $3 million, cooperate with plaintiffs and waive commissions' 'to the realtor-buyer.

The MLS PIN agreement will be the first in Boston in this litigation. The other two defendants, Re/Max and Anywhere Real Estate, recently said they will settle their claims in similar cases in Illinois and Missouri courts. Anywhere planned to pay $83.5 million, according to a statement on the National Association of Realtors' Web site.'' 'Re/Max said in a document to the regulator that it would pay $55 million. Both agreements require court approval. Re/Max declined to comment on the Massachusetts case. Anywhere also declined to comment.

The case is Nosalek et al v. MLS Property Information Network Inc et al, Massachusetts District Court.

For the plaintiffs: Robert Izard and Seth Klein of Izard, Kindall & Raby; and Christopher Lebsock and Jose Roman Lavergne of Hausfeld.

For MLS PIN: John Anderson of Scungio & McAllister.

For EU PIN: Jessica Leal of the Department of Justice.