Aecom has bought fellow US consultant Tishman Construction for $245m (£160m)
Tishman, a provider of construction management services in America and the UAE, generated revenue of about $1bn in 2009. Among its projects is the rebuilding of the World Trade Centre in New York.
Aecom said the purchase would expand its presence in the high-margin programme management sector, which the firm estimates is worth more than $100bn.
Aecom recently obtained credit worth $250m. It said some of this would be used to pay for Tishman.
The company is understood to be close to acquiring UK consultant Davis Langdon.