By Mike Spector and Greg Roumeliotis

(Reuters) - The U.S. Treasury Department has hired Wall Street bankers and lawyers to advise on providing tens of billions of dollars in aid to the airline, cargo and defense sectors, people familiar with the matter said on Wednesday.

The appointments come after U.S. lawmakers approved a $2.2 trillion stimulus bill last week to mitigate the economic fallout of the coronavirus pandemic, which has killed more than 5,000 people in the United States and shut down large swathes of the country's economy.

PJT Partners Inc <PJT.N> will advise the Treasury on its negotiations with the airlines, the sources said. The stimulus bill, known as the CARES Act, provides for up to $50 billion in aid to airlines, half of it in loans and loan guarantees and half of it in grants.

Moelis & Co <MC.N> will advise the Treasury on its negotiations with companies in the cargo sector, for which $8 billion has been allocated, to be split equally between loans and grants, according to the sources.

Perella Weinberg will advise the Treasury on its negotiations with companies that are active in industries important to national security, such as Boeing Co <BA.N>, according to the sources. The CARES Act has allocated up to $17 billion for these companies.

Law firm Cleary Gottlieb Steen & Hamilton LLP will also be advising the Treasury on the negotiations, the sources said.

Moelis, Perella Weinberg, PJT and Cleary declined to comment. The Treasury did not immediately respond to a request for comment. The Wall Street Journal first reported on the role of the investment banks on Wednesday.

The new legislation requires equity, warrants or other financial compensation for taxpayers for the $25 billion in loans, but gives Treasury Secretary Steven Mnuchin discretion over whether to seek compensation for the grants. Mnuchin has said in several interviews that the aid that will be provided "is not a bailout".

The Treasury has asked the airlines to propose financial instruments as part of their applications for grants that they want to see by Friday. U.S. House Speaker Nancy Pelosi urged the Treasury on Wednesday not to hold up the cash grants to the airlines.

Airlines have grounded many of their flights to comply with restrictions on travel and a dramatic plunge in flight bookings as officials order citizens to remain home to curb the global spread of coronavirus. The International Air Transport Association estimated in late March that lost revenue from the crisis will exceed $250 billion in 2020, and urged governments to offer immediate financial support to the industry.

The airlines have asked the Treasury to allocate grants in accordance with salaries and benefits they pay to employees.

(Reporting by Mike Spector and Greg Roumeliotis in New York; Additional reporting by Bhargav Acharya in Bengaluru, Jessica DiNapoli in New York, and David Shepardson and David Lowder in Washington, D.C.; Editing by Jacqueline Wong)