Etihad Airways said on Friday that the US government has provided America's three biggest airlines with more than $70 billion in benefits and concessions, citing a report it commissioned.
The Abu Dhabi-based airline has itself come under attack from US rivals over subsidies.
"US airlines have received benefits valued at $71.48 billion, more than $70 billion of which has been since 2000, enabling the nation's three largest carriers to transition from the verge of bankruptcy to today's industry leaders," a statement from Etihad said.
Last year, the three largest US carriers posted profits of almost $9 billion, close to half the gains racked up by the entire worldwide aviation industry, the airline added.
In early March, American Airlines, Delta Airlines and United Airlines, along with US airline labour groups, accused Gulf carriers of enjoying interest-free loans, subsidised airport charges, government protection on fuel losses, and below-market labour costs that are considered unfair subsidies by the World Trade Organization.
They called on the US government to open new talks over bilateral air agreements to address what they said are violations of those pacts, giving the Gulf carriers unfair competitive advantage.
Etihad general secretary Jim Callaghan said his airline's study was not intended to criticise the subsidies US competitors received.
"We simply wish to highlight the fact that US carriers have been benefitting and continue to benefit from a highly favourable legal regime, such as bankruptcy protection and pension guarantees, exemptions from certain taxes, and various other benefits," he said.
Callaghan said the benefits had "created a highly distorted market in which carriers such as Etihad Airways have to compete."