Consulting firm Sinclair Knight Merz (SKM) says its $1.3 billion take-over by global engineering giant Jacobs Engineering will help boost the firm's market position.

SKM chief executive Santo Rizzuto said the move "uniquely positions us amongst our global peers and opens the way for us to achieve even greater things in the future".

"It adds scale, diversification and growth opportunities to our business," he said in a statement.

SKM is wholly owned by its employees and the take-over proposal will need to be approved by shareholders, but the company's board of directors has unanimously endorsed the deal.

The company, founded in Sydney in 1964, employs more than 6,500 employees and generates fee income in excess of $1 billion a year.

It operates in Australia, Asia, South America and Britain, and serves clients in the mining, building, water and power businesses.

California-based Jacobs Engineering provides technical and construction services to a various businesses including those in the aerospace, automotive, energy and pharmaceuticals industries.

It had a revenue of $US11 billion in its fiscal 2012 and employs 65,000 employees in 200 locations with offices in 25 countries in the Americas, Europe, the Middle East, India, Australia, Africa and Asia.

Its chief executive, Craig Martin, said in a statement that the two companies' geographic regions and capabilities had little overlap.