The Brisbane based civil engineer has been renamed Murphy Pipe and Civil following the takeover.
Murphy Pipe and Civil employs around 200 staff and specialises in building pipelines.
The move is a radical departure for Murphy which has established itself as one of the leading names in the UK utilities and civil engineering markets during the last 60 years.
Australia is seen as a growth market for UK contractors and Laing O’Rourke is rapidly expanding its operations in the country.
One industry expert told the Enquirer: “Australia is definitely an attractive market but it’s quite a surprise to see Murphy getting involved over there.
“They have traditionally been a fairly conservative firm but everyone has to react to market changes.”