Environmental consultant SLR Consulting has bought waste treatment specialist Waste Management Engineering (WMEL) for an undisclosed fee.
WMEL advises blue chip companies such as Pfizer, manufacturers of the erectile dysfunction tablet Viagra, on waste treatment and pollution control.
SLR Consulting said it had acquired WMEL as part of its strategy to extend the range of waste management services it offers to industry, local and national government and regulatory authorities.
SLR Consulting managing director Neil Penhall said: "WMEL has worked successfully with us on numerous waste and process related projects over the last seven years.
"The merger makes sound economic sense and offers excellent growth opportunities, particularly in the waste processing and renewable energy markets."