Nuclear waste management company EnergySolutions Inc will be bought by a unit of private equity firm Energy Capital Partners II LLC for $338.5 million in cash.

The deal has an enterprise value of $1.1 billion, the companies said in a statement.

EnergySolutions' shareholders will receive $3.75 in cash for each share, representing a 9 percent premium to the stock's Friday's close of $3.44 on the New York Stock Exchange.