June 9 (Reuters) - Sunnova Energy ( NOVA ) said on

Sunday it had filed for Chapter 11 bankruptcy protection in the

United States, as the residential solar panel installer buckled

under the pressure of mounting debt and weakening demand.

Shares were down 36.4% at 14 cents in premarket trading.

Sunnova filed for protection in the Bankruptcy Court for the

Southern District of Texas after warning in March that it might

not be able to continue as a going concern.

The company listed its estimated assets and liabilities in

the range of $10 billion to $50 billion and has a total debt of

$10.67 billion as of December 31, according to a court filing.

Sunnova said last week it would lay off about 55% of its

workforce, or 718 employees, in a bid to cut spending.

Earlier this month, its unit, Sunnova TEP Developer, had

also filed for Chapter 11 bankruptcy protection.

The company's bankruptcy filing comes at a time when the

U.S. residential solar energy industry is under immense pressure

from higher interest rates; a reduction in incentives in the top

market, California; and fears of subsidy rollbacks for clean

energy.

President Donald Trump's administration, which is pushing to

maximize oil and gas production, canceled a partial loan

guarantee of $2.92 billion last month that was awarded to

Sunnova by the Biden administration.

Last year, peer SunPower, once a pioneer of the

U.S. residential solar market, also collapsed following a

subpoena from the U.S. Securities and Exchange Commission about

its accounting practices and the departure of its CEO.

Companies that put solar panels on U.S. homes said last

month a Republican budget bill that has advanced in Congress

could deal a massive blow to the industry by eliminating a

generous subsidy for homeowners that had buttressed the

industry's growth.