Aer Lingus and Etihad Airways are expected to announce a code share agreement following three months of negotiations. The deal will allow both carriers to sell flights to each other’s customers and will give the Abu Dhabi-based carrier greater access to transatlantic routes out of Dublin.

Earlier this year, Etihad purchased a 2.98 per cent share in the Irish airline and the code share deal is being seen by many as an indication that the carrier wants to increase its stake. However, European legislation means that Etihad will not be allowed to take a majority share.

The airline’s chief executive James Hogan said last week that he would be interested in setting up a meeting with Irish ministers to discuss buying the government’s 25 per cent share. Aer Lingus rival Ryanair has also expressed an interest in the shares and has even offered to pay €1.30 for each.

However, any deal between Ryanair and Aer Lingus would have to gain the approval of Europe’s competition regulators because of the pair’s dominance in Ireland. Etihad already has shares in airlines including Air Seychelles, Air Berlin and Virgin Australia, which it claims are yielding benefits.

Air Berlin said that it had managed to save around €100 million in costs through its relationship with Etihad. The German carrier has saved money by sending its pilots to Etihad for Boeing 787 simulator training rather than having to invest in the technology itself.