The firm’s Regional and City Airports arm has acquired a 95 per cent share from Northern Ireland based property developer Mar Properties.
The sale is subject to receiving the approval of the remaining minority shareholder Blackpool Borough Council which is expected by Friday.
Balfour Beatty chief executive Ian Tyler said: “We believe that our approach will deliver significant, sustained growth in passenger traffic at the airport and will generate important economic benefits for it and for Blackpool.
“Our aim is to develop Blackpool to be the airport of choice for residents, businesses and visitors of Lancashire and Cumbria.”
Blackpool International Airport is situated one mile south of Blackpool town centre with road and rail links which provide fast access to the north-west.
The airport is forecast to handle about half a million passengers in 2008, flying 12 routes to the UK, Ireland, Isle of Man and mainland European destinations.
RCA acquired Exeter International Airport for £60 million in January 2007.