Atkins is to acquire American consultant PBSJ for £178m.
PBSJ is one of America's leading providers of engineering, planning, architecture, construction, environmental and programme management services. It is employee-owned and based in Florida.
At 31 March 2010, PSBJ employed approximately 3,500 people and in the year to 30 September 2009 generated earnings of £30m on revenue of £508m.
Atkins said the acquisition would “balance its geographic presence” and “deepen the Group's technical skills in established sectors”.
Keith Clarke, chief executive of Atkins, said: "This is an important acquisition for Atkins and forms part of our plan to grow our business through a multi-skill, multi-local strategy.
“PBSJ operates a business model we understand and complements our business superbly, enhancing our skills in environmental, transportation, building design and programme management disciplines.
“PBSJ has an experienced management team and a strong, long-standing reputation for technical excellence and quality, which underpins its deep client relationships.
“These are all important criteria for a successful acquisition which will provide us with a strong platform for growth and enable us to drive significant value for our shareholders."
Meanwhile, in an interim management statement for the period from 1 April 2010 to date, Atkins said it was “trading in the first quarter in line with our expectations”.
However, it added that its UK building design business “has been impacted by the cancellation of some projects under the Building Schools for the Future programme”.