The move creates a consulting powerhouse employing 74,000 people globally.

Jacobs highlighted CH2M’s expertise in major UK transport projects as a key driver of the deal.

Steve Demetriou, Jacobs’ Chairman and CEO said: “By increasing our industry reach and adding to our already extensive skills, this transaction enhances our value to our clients and bolsters Jacobs’ position as a premier consulting, design, engineering, construction, and operations and maintenance technical services firm.

“CH2M brings to Jacobs a talented, engaged team with capabilities and values that are very complementary to our own.’

Jacobs has already identified £113m of cost savings from combining the companies.

CH2M Chairman and CEO Jacqueline Hinman said “Since late 2014, we’ve been transparent about our plans to pursue an ownership transition, providing sustained access to capital for growth.

“Considering all of the options, we focused on securing greater opportunities for our employees, delivering superior value to our clients and enhanced value for our stockholders, all while continuing to serve the higher purpose our company is known for, providing sustainable solutions for a better world.”