Concerns about the ability of Macao casino operators to raise funds for projects and China's efforts to cool the city's gaming market have caused a run on their stocks.

Operators have had a difficult time as the Chinese government has tightened the frequency with which mainland gamblers can travel to Macao, in an attempt to tame the market's growth.

Gaming revenues, which rose more than 50 per cent in the first six months of this year, were flat in the first half of September, Standard & Poor's said.

Meanwhile, casino operators have announced ambitious projects.

China's determination to take the steam out of the sector could lead to a drop in cashflows or earnings, which may force companies to repay their loans early or affect their ability to raise new funds.

Galaxy Entertainment is estimated by UBS to have a funding gap of HK$4bn ($514m). Shares in Galaxy have fallen 72.7 per cent in the past six months and Sociedade de Jogos de Macau, the gaming flagship of tycoon Stanley Ho, is down 47 per cent.