CityJet and Spain's Air Nostrum have announced a deal to create the largest pan European regional airline group.
The new group will have a combined fleet of almost 100 aircraft and annual revenues of about €700m.
The airline said the deal aims to bring about closer co-operation between the two airlines under the umbrella of a new holding company.
It said the development is still subject to obtaining the requisite regulatory approvals and the preparation of the relevant filings has begun.
Air Nostrum, which employs 1,450 people, is the regional operator for Iberia and flies to more than 60 destinations within Europe and Africa.
It has a fleet of 50 aircraft, including 30 Bombardier CRJ1000 regional jets.
CityJet employs 1,250 people across nine European countries and operates a regional network of services under wet lease contracts with Air France, Brussels Airlines and SAS with a fleet of over 40 aircraft across Europe.
This fleet includes 22 new Bombardier CRJ900 regional jets acquired specifically for wet lease services.
The two airlines are of very similar age, with CityJet founded in 1993 Air Nostrum in 1994.
Pat Byrne, CEO of CityJet, said the two airlines' large fleets of Bombardier CRJ 900 and CRJ 1000 aircraft is "a robust and economic platform" which is ideal for wet lease contracts.
"By coming together, we believe we will be in a position to respond to the specific needs of customer airlines through our flexibility in the provision of safe, dependable and quality assured operations," Mr Byrne added.
Today's deal was announced at the Farnborough Airshow in England.