Scientific Games Corp. agreed to acquire Bally Technologies Inc. in an all-cash deal that values the slot-machine maker at about $3.3 billion.

According to the companies, the deal is valued at $5.1 billion, including the refinancing of about $1.8 billion of existing Bally debt.

Bally shareholders will get $83.30 a share, representing a 38% premium to Bally's closing price on Thursday. Bally shares jumped 36% to $82.00 in light premarket trading.

The deal expands Scientific Games' portfolio to include leading casino management systems and table products, including automatic shufflers, proprietary table games and electronic table systems, the companies said.

Scientific Games and Bally generated combined revenue of about $3 billion in the one-year period ended March 31, and the companies noted that Scientific Games expects to realize $220 million of cost synergies and $25 million of capital expenditure savings by consolidating operations and creating efficiencies in the areas of manufacturing, engineering, field and customer service, and administrative operations.

Once the deal is closed, Scientific Games Chief Executive Gavin Isaacs is expected to continue in his post, while Bally CEO Richard Haddrill and Bally Chairman David Robbins, will join the board of Scientific Games, the companies said. Mr. Haddrill is expected to serve as vice chairman, they added.

The acquisition is expected to be completed early next year. The transaction was unanimously approved by the boards of both companies.

Write to Anna Prior at anna.prior@wsj.com

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