Feb 10 (Reuters) - Casino operator MGM Resorts posted a bigger-than-expected loss on Wednesday, hurt by COVID-19 travel restrictions, but signaled a pickup in demand later this year as vaccines become more widely available.

The company said it expects demand in Las Vegas to strongly pick up later in the year, adding that gross bookings in January were the strongest since the start of the pandemic.

"We are optimistic with what we see on our books in the third and fourth quarter," Chief Operating Officer Corey Sanders said on a post-earnings call.

MGM also expects its sports betting unit, BetMGM, to be in 20 markets by the year-end as companies move to capitalise on an expected boom in online sports betting fuelled by pandemic lockdowns.

Last month, MGM ditched plans to buy Ladbrokes owner Entain after the British company rejected an $11 billion takeover approach, aimed at expanding jointly operated BetMGM. Revenue from the company's main casino business fell 40.9% to $963.8 million. Total revenue fell 53.1% to $1.49 billion, missing analyst estimates of $1.52 billion, according to Refinitiv data.

Net loss attributable to the company was $447.6 million, or 92 cents per share, in the quarter ended Dec. 31, compared with a profit of $2.01 billion, or $3.91 per share, a year earlier.

Analysts on average expected MGM to lose 90 cents per share in the fourth quarter.

Total liquidity was $8.8 billion as of Dec. 31, 2020, at MGM.

Shares of the company were down 1.5% in extended trading. (Reporting by Sanjana Shivdas in Bengaluru; Editing by Ramakrishnan M.)