The government is set to announce that Britain's Search and Rescue service is to be sold off to an American firm.
Up until now, the operation has been run by the RAF, Navy and Coastguard Agency.
The firm will actually be awarded two contracts, because the service has been separated into two parts operating different types of helicopter.
An announcement is expected just before the stock market opens in the morning.
Half of the new fleet will be built at AgustaWestland in Yeovil. The contract will have a significant impact on the UK supply chain, providing and sustaining jobs and apprenticeships.
Under the new contract, 22 state-of-the-art helicopters will operate from 10 locations around the UK.
Ten Sikorsky S92s will be based, two per site, at Stornoway and Sumburgh in Scotland, and at new bases at airports in Newquay in Cornwall, Caernarfon in Wales and Humberside.
Ten AgustaWestland AW189s will operate, two per site, from Lee on Solent and a new hangar at Prestwick Airport, and new bases which will be established at St Athan, Inverness and Manston airports
All bases will be operational 24 hours a day.
The new contract will be managed by the Maritime and Coastguard Agency in the same way as the existing contract that operates the Coastguard helicopter bases on the south coast and on the Western and Shetland Isles.
The deal for Bristow Helicopters to run the country's search-and-rescue (SAR) helicopter service is worth £1.6 billion.
It ends ends 70 years of SAR service from the RAF and the Royal Navy SAR squadrons. It also spells the end of the use of Sea King helicopters in SAR work. It is not known whether Portland, Culdrose or Chivenor will be affected.
The Department for Transport has confirmed the contract to run the UK's search-and-rescue helicopter service has gone to the US-headquartered Bristow Helicopters.