Abu Dhabi's Etihad Airway's contribution to the U.S. economy will almost double to $6.2 billion by 2020, it said on Wednesday, in an apparent counter to allegations that government subsidies gave it an unfair edge over competition.

The airline will support the American economy with 23,400 jobs and $2.9 billion in 2015, according to research by Oxford Economics, Etihad said in  a statement.

Both of the figures will nearly double by 2020 as Etihad increases operating expenditure and capital investment.

Etihad said the study assessed its capital expenditure with U.S. suppliers and its operating expenditure, as well the impact of passengers it brought into the country.

Three U.S. airlines - Delta, United and American, earlier this year launched a campaign, asking for their Open Skies pact with Gulf carriers to be altered.

In a lengthy report, the airlines accused Etihad, Emirates and Qatar Airways of taking $40 billion in government subsidies, allowing them to lower prices and push U.S. competitors out of certain markets.

"Open Skies is good for competition and good for the consumer, but most of all today's report shows it is also good for the American economy," Vijay Poonoosamy, vice president of international and public affairs at Etihad said.

While denying these accusations, Etihad compiled a report in reply, saying the three U.S. airlines had received $70 billion in government support since 2000, largely through bankruptcy protection and pension guarantees.

The carrier has said it will compile an official reply by the end of May.

Etihad maintains it has received equity and loans from its sole shareholder, the government of Abu Dhabi.(by Nadia Saleem)