The Isle of Capri, which opened the first casino in Vicksburg in 1993, is returning to the city pending approval by the Mississippi Gaming Commission of its purchase of the Rainbow development for about $80 million.

Bally Technologies, owner of Rainbow, and officials of Isle of Capri announced the planned transaction Monday afternoon.

The motive for the sale has been cited before. Rainbow had been the lone casino operated by Las Vegas-based Bally Technologies, which specializes in developing slot machines and gaming software. In a conference call with investors Monday, Bally Chief Executive Officer Richard Haddrill said the sale of Rainbow “will allow us to concentrate on our core business.”

“We have enjoyed a successful, 16-year run owning and operating Rainbow Casino, and have made a number of improvements to the facility which have enabled it to grow its business, even in a very competitive environment,” Haddrill said. “We feel confident that under the ownership of Isle of Capri, Rainbow and its employees will be in very competent hands.”

Details such as whether the new owners will continue to use the Rainbow name, brand the site as an Isle of Capri or select another name were not available. Rainbow, the fourth and final casino to open in the initial round of construction after Mississippi opened coastal and Mississippi River counties to casinos in 1990, has about 300 employees, 830 slot machines, 10 table games, an 89-room hotel and two restaurants.

“All I can really say at this point is we’re excited to become a part of the Isle of Capri family,” said Rainbow spokesman Mickey Fedell.

The Isle of Capri, a company founded when riverboat gambling was approved in Iowa, opened the first Vicksburg location by docking a boat and a barge on property at 3390 Washington St., in August 1993. Over the next several months, it was joined by Harrah’s, Ameristar and Rainbow. Gradually, the Isle of Capri added a permanent casino structure and hotel.

In February 2006, the Isle sold its Vicksburg holdings to privately held Legends Gaming, which changed the casino’s name to DiamondJacks and has operated it since.

Based in St. Louis, Isle of Capri operates 15 casinos in six states under four brands, including the lone casino in Natchez and others in Biloxi and Lula.

In October 2006, it was announced that Bally had hired a firm to sell its 35,000-square-foot riverfront property at 1380 Warrenton Road. However, in August 2007 the company announced it was pulling the casino from the market.

When it opened in July 1994, Rainbow Casino was the only development south of the Mississippi River bridges. Since then, Riverwalk Casino opened next door in October 2008.

With the transaction, only Ameristar remains under original ownership. Harrah’s sold and is now Horizon.

Bally’s sale of Rainbow to Isle of Capri has been approved by directors of both companies and the transaction is expected to close by June 30.

Shares of Bally stock rose on news of the sale Monday by $1.43, or 3.5 percent, to $42.33. Isle of Capri shares climbed 71 cents, or 8.8 percent, to $8.76.