Edmonton-based Stantec will pay a combination of cash and stock to shareholders of Irvine, Calif.-based Keith Cos.

Both firms provide engineering, architecture and planning services and both are publicly traded with shares listed in exchanges in their respective countries. In 2004, Keith Cos.' revenues were $105.3 million while Stantec's were $398.4.

"This is an exciting transaction for The Keith Companies' employees, clients, and shareholders," says Aram Keith, chief executive officer. "Joining Stantec will substantially accelerate our growth plans and make the Keith Cos. a part of a North American firm with a widely diversified service offering."

Stantec's cash and stock offer represents an approximate 30% premium to the Keith Cos. closing price on April 14, says Keith.

tantec has agreed to buy the Keith Cos.