After four years and innumerable delays, the checks may—at long last—be in the mail.

The De Beers antitrust class action settlement was finalized on May 21, when the Supreme Court denied an appellant’s motion for reconsideration.

Plaintiff attorneys say members of the direct class—trade companies that purchased directly from De Beers and other miners—should have started receiving their checks in June and July. “Indirect” trade members should start receiving their checks after that, with consumer checks going out later this summer.

“This normalizes business for De Beers in America,” says De Beers director of communications David Prager. “If you think about the past century, this is a milestone moment.”

“A lot of the past restrictions we have had previously are now gone,” he says. “We have clearly not jumped into America with both feet, and we have resisted contracting with American companies. When you have normalized business in the States, a lot of those things fall away and you have a lot more opportunities.”

The $300 million settlement was first reached in 2006 and approved by a Federal judge in 2008. But in July 2010, a court ruling from the Third Circuit overturned the original settlement. A subsequent decision by the en banc panel of the Court of Appeals of the Third Circuit reinstated the decision 10 months later. One appellant then decided to appeal to the Supreme Court.

In addition to mandating that De Beers distribute $300 million to direct and indirect purchasers of diamonds, the settlement also mandates that De Beers refrain from engaging in conduct that violates federal and state antitrust laws. The suit charged that De Beers had monopolized the price of diamonds and conspired to fix, raise, and control diamond prices. De Beers has denied wrongdoing.