Hilton Worldwide Holdings Inc on Wednesday posted a surprise quarterly loss as bookings took a hit from a resurgence in COVID-19 cases and renewed travel curbs, sending shares of the U.S. hotel operator down 2.3% in premarket trading.

Although occupancy rates have bounced back from April 2020 lows thanks to a relative easing of lockdowns, emerging variants of the virus have hindered a swift recovery for U.S. hotel operators.

"Rising COVID-19 cases and tightening travel restrictions disrupted the positive momentum we saw throughout the summer and fall," Chief Executive Officer Christopher Nassetta said in a statement.

Analysts expect a wider rollout of COVID-19 vaccines later this year to first aid a rebound in leisure travel, leaving hotel chains including Hilton and larger rival Marriott which rely more on business travel, struggling for longer.

Hilton, the first major hotel chain to report earnings, said fourth-quarter revenue per available room (RevPAR) — a key measure for a hotel's top-line performance — fell about 59% to $40.68, and was below the company's expectation of about $45 per room.

Net loss attributable to Hilton stockholders was $224 million, or 80 cents per share, in the quarter ended Dec. 31, compared with net income of $175 million, or 61 cents per share, a year earlier.

On an adjusted basis, Hilton lost 10 cents per share, missing analysts' estimates for a profit of 3 cents per share, according to Refinitiv data.

Revenue plunged 62% to $890 million, below Wall Street's estimate of $1.03 billion.