Energy infrastructure company Chicago Bridge & Iron Company NV (NYSE: CBI) will buy The Shaw Group Inc. (NYSE: SHAW), a Baton Rouge, La.-based engineering and construction firm, for about $3 billion in cash and stock, the companies said Monday.

The Woodlands, Texas-based CB&I, which is based in the Netherlands, will acquire Shaw for $46 a share in cash and stock. Shaw shareholders will receive a premium of 72 percent over Shaw's closing stock price of $26.69 on Friday. That means they will get $41 in cash as well as CB&I stock worth about $5 for each Shaw share.

The combined entity is expected to hire about 50,000 people and expand its presence in the energy market.

Shaw shares climbed $15.21, or 57 percent, to $41.90 in late morning trading Monday. Meanwhile, CB&I shares fell $6.51, or 16 percent, to $34.08.