* April revenue $3.9 billion ahead of May holiday
* Mass market to accelerate growth versus VIP
* Junkets under more scrutiny
(Adds details on VIP, mass market segments, junket operators)
HONG KONG, May 2 (Reuters) - Macau, the world's casino capital, raked in 31.3 billion patacas ($3.92 billion) in gambling revenue in April thanks to strong spending by Chinese visitors keen to place their bets in the country's only legal casino hub.
Gambling revenue growth in Macau, a special administrative region like neighbouring Hong Kong, was up 10.6 percent in April, beating analyst estimates of 6-8 percent growth.
A Portuguese colony until 1999, Macau earns the equivalent of Las Vegas' annual haul in less than two months. Annual revenues reached a record $45 billion in 2013, elevating the tiny territory high above rival gaming destinations.
Gambling appetites are seasonally more subdued in April ahead of a national holiday week in May when record swathes of visitors are expected to travel to Macau, a tiny territory one-third the size of Manhattan.
While 2013 saw rapid gambling revenue growth, analysts have tempered expectations for the coming year due to macro economic uncertainties in China and the potential for slower credit growth that could impact liquidity of the VIP segment.
The VIP segment, made up of high-rollers from the mainland, has for the past several years driven the bulk of Macau's casino business, making up 70-80 percent of overall gaming revenues.
However in the past year, lacklustre growth has seen the VIP segment usurped by the rise of China's burgeoning middle class who now account for more than a third of total revenues.
Junket operators, who loan Chinese VIPs millions of yuan to play in Macau, have come under increased scrutiny over the past year as a crackdown on corruption by Beijing has prompted a closer eye on their lending practises.
A recent high profile arrest of a large shareholder of a Macau junket operator in March and the disappearance of a small-scale junket investor in April has dampened sentiment for the high-roller segment with analysts predicting tighter liquidity and less risk-taking as a result.
Charlene Liu, an analyst at HSBC in Hong Kong, said the impact of the disappearance of a junket operator who left with HK$8 billion-HK$10 billion ($1.03 billion-$1.29 billion) may surface in the gaming revenue numbers in mid-May.
While the junket sector can yield huge revenues, the flows are more volatile and less profitable for casino operators who are forced to pay the operators hefty commissions.
One of the world's fastest-growing economies for the last three years, Macau has been a gold mine for gaming operators like U.S. billionaires Sheldon Adelson and Steve Wynn. Their companies, Sands China and Wynn Macau, are expanding on Macau's Las Vegas-style Cotai strip along with the four other licensed operators - MGM China Holdings Ltd , Melco Crown Entertainment Ltd, Galaxy Entertainment Group Ltd and SJM Holdings Ltd .
While no new casinos are set to open in Macau this year, the gambling hub will see the opening of eight new resorts over the next three years.
Low penetration and improving infrastructure developments that will shorten the journey from the mainland to Macau are likely to continue to drive visitor growth and demand for gambling, analysts say.
Across the water from Macau's gleaming casino towers is Hengqin island, a plot of land three times the size of Macau that China is developing into a leisure and innovation hub.
Expansion in Macau and the surrounding area comes as rival gaming destinations from the Philippines to Vladivostok in Russia set up casino resorts to lure wealthy Asian punters.
Local authorities and top officials in Beijing are pushing to diversify Macau away from its reliance on gaming. The expansion of facilities for entertainment, retail and conventions are intended to attract a wider visitor base who come to Macau for leisure and tourism rather than to gamble.
($1 = 7.9860 Macau patacas)
($1 = 7.7531 Hong Kong dollars)
(Editing by Matt Driskill)