TRANSCO is set to appoint two contractors to carry out maintenance work worth up to £77.5 million.
Morrison is tipped to win a contract valued at up to £55 million over five years for the pipeline operator's southern local district zone, beating off competition from Alco, Amec and Bartholomew.
The deal covers the South Coast between Bognor Regis and Lyme Regis and stretches from the Isle of Wight in the south to Milton Keynes in the north.
The contract comprises the amalgamation of two separate areas, Wessex and Ridgeway, into one deal covering the South of England.
The job is worth £11 million-a-year for three years plus an option to extend for a further two years.
The incumbent for Ridgeway is Alco, while Bartholomew holds the Wessex contract. An official award is imminent.
Meanwhile, four contractors are battling for control of the contract for Transco's northern local district zone, which stretches from Berwick- upon-Tweed in the North-East across to Carlisle, down to Penrith and across to Middlesbrough.
Bidders chasing the deal, which is worth up to £22.5 million, include Alco, Kennedy, Dewsbury Civil Engineering and Kenton.
One bidder said: 'It's a big geographical area but there is not the same density of population as other smaller areas.'
The contract is worth about £4.5 million for three years, with an option to extend for a further two years.
Transco initially interviewed 10 firms that registered interest in the deal before whittling the list down to four.