The Obama administration on Friday solicited comments from interested parties about US airline and unions' claims that Gulf carriers have received market-distorting subsidies, marking the latest step in its review of the matter.

"The US government takes seriously the concerns raised," the US departments of State, Commerce and Transportation said in a joint statement. The review of submitted materials is expected to begin by the end of May.

US carriers and unions allege that Emirates Airline, Etihad Airways and Qatar Airways benefit from more than $40 billion in state subsidies that have allowed them to drive down ticket prices and begin pushing US airlines out of key markets. They have called on the Obama administration to request consultations on the matter with those airlines' home governments, the UAE and Qatar.

The Gulf carriers have denied the subsidy allegations and said US airlines' worse service has caused them to lose market share.

American Airlines Group, Delta Air Lines and United Continental Holdings submitted the claims about subsidies.

"Etihad Airways is committed to setting the record straight regarding these unsubstantiated allegations," the airline said in a statement, applauding the US government's transparency. "We hope that no one will pre-empt this process or prejudge its outcome."

All material received by the interagency team will be made public, unless the departments approve requests by interested parties, if any, to keep particular information confidential, the Obama administration's statement said.

"We are pleased that the US government is taking the next step to further examine the issue," Jill Zuckman, spokeswoman for the US airline and unions' group, said in a statement. "This process is an opportunity for more transparency and we urge the Gulf carriers to adhere to the same standards of financial disclosure and accountability as the US carriers." - Reuters