Virginia officials will announce Monday that Bechtel, one of the largest engineering, construction and project management companies in the world, will relocate its global operations headquarters from Frederick to Fairfax County, according to sources in Fairfax and Richmond.

The move to Reston Town Center will bring 625 jobs and an $18 million investment.

Fairfax will house the San Francisco-based company’s government services unit, its U.S.-based civil business unit, Bechtel Enterprises and its local corporate functions and services.

Virginia Gov. Robert F. McDonnell (R) approved a total of $6.5 million in grants: $1.5 million from the Governor’s Opportunity Fund and $5 million from the Virginia Economic Development Incentive Grant.

Maryland officials approved a $9.5 million loan to keep an additional 1,250 Bechtel jobs in the state last month. Bechtel will also retain an office in McLean.

 The century-old company with nearly 45,500 employees and 22,000 projects in more than 100 countries provides technical and management services to develop, manage, engineer, build and operate installations for customers worldwide. It reported annual sales of $27 billion in 2010.

In recent weeks, McDonnell has taken several swipes at Maryland as not being friendly enough to business. “Maryland, with some of their tax and regulatory policies, [has] been less friendly to business,” he said recently.

Virginia officials are also pursuing Lockheed Martin after Maryland’s Montgomery County Council talked about passing a resolution asking Congress to spend less on wars, angering the company, which employs more than 5,000 workers there.

Maryland has lost at least two defense contractors to Virginia in recent years. Last year, Northrop Grumman chose Virginia over Maryland for its global headquarters after a process that pitted the neighboring states against each other. The defense firm moved to Falls Church this summer.

Staff writers Aaron Davis and Laura Vozzella contributed to this report.