Boyd Interactive has purchased Resorts Digital, the online gambling arm of Atlantic City’s Resorts casino, for an undisclosed amount.

Mark Giannantonio, president of Resorts, said Monday that the transaction was finalized on Sept. 1. Neither company would reveal the purchase price.

Resorts Digital has outperformed the physical Resorts casino for years; it has taken in five times the amount of money from gamblers over the first eight months of this year as the physical casino did.

Over that period, Resorts Digital won over $573 million, compared to $109 million for the physical Resorts casino, according to the New Jersey Division of Gaming Enforcement.

In terms of profitability, Resorts Digital posted a gross operating profit of $9.6 million in the first half of this year, up 5.6% from the same period a year ago. In contrast, the physical Resorts casino had a gross operating profit of $355,000 in the first half of this year, down almost 89% from a year earlier.

Boyd Interactive, part of Las Vegas-based Boyd Gaming, received ResortsCasino.com and MoheganSunCasino.com in the deal, along with one unused sports betting skin, or online identity.

Resorts Casino will keep its relationship with other online gambling partners including DraftKings, Penn Gaming, PokerStars and ESPNBET.

“We are confident that this transaction will propel Resorts Digital’s proven success over the past decade to a new level through the scale of Boyd Interactive and its market-leading platform,” Giannantonio said in a statement.

Boyd said in a statement that the purchase “is consistent with Boyd Gaming’s strategy of building a profitable regional iGaming business integrated with our existing nationwide portfolio.”

“New Jersey has long been one of the nation’s leading iGaming states, and we look forward to further growing our presence in that state’s online gaming market in partnership with Resorts Casino in Atlantic City,” Boyd said.

Boyd used to be half-owner of Atlantic City’s Borgata casino before selling its interest to MGM Resorts International.

Even though it is now owned by Boyd, Resorts Digital will continue to operate under the sports betting and internet gambling licenses held by Resorts Casino, Giannantonio said.

The two companies will cross-promote each other, with Resorts promoting the ResortsCasino.com brand on the physical premises of its casino. Meanwhile, ResortsCasino.com will promote Resorts Casino Hotel in Atlantic City to its online customers.

“This marketing relationship will benefit both companies in the long term,” Giannantonio said.

Resorts is owned by New York real estate executive Morris Bailey and his business partner Joseph Jerome.