Asian chief executive officers have been the most optimistic in the world since the breakout of the global financial crisis, but a recent survey shows that optimism is waning.

The survey of 2000 global members of the Young Presidents Organization indicates that the YPO Global Pulse index for Asia edged lower by 0.2 points in the fourth quarter of 2011 to 60.7, significantly lower than the high 60s of earlier quarters going back to 2009, soon after the breakout of the global crisis.

From mid-2009 through the third quarter of 2010, Asian confidence was roughly 10 points higher than the global index. Since then, the gap has steadily narrowed, and now for the first time, Asia weighed in slightly lower than the global index average. Asian confidence at 60.7 in this latest reading trails Canada (64.4), Latin America and Africa (both at 63.6), and the United States (62.2).

“The Chinese government is putting on the brakes, imposing lending restrictions, and it’s clearly reflected in our results,” says Stanley Szeto, the incoming chairman of the Hong Kong chapter of YPO, which has 19,000 members globally (CEOs who are below the age of 50), including more than 1000 in Asia and 80 in Hong Kong. “People were used to easy credit, and all of a sudden it’s no longer so easy. So people are feeling a bit uneasy.”

Paul Schulte, Hong Kong–based global head of financial strategy and Asia banks research at CCB International Securities, a subsidiary of China Construction Bank, estimates that Chinese regulators have sucked up $700 billion in liquidity from the financial system in the past 12 months. This would be in addition to the 4 trillion yuan stimulus the government pumped into the economy in 2009, which helped China to drive growth in excess of 10 percent both that year and in 2010, cushioning the entire Asian region from the worst of the global crisis.

That stimulus, however, also caused property prices to triple in major Chinese cities and sent inflation up to nearly 7 percent, the highest in nearly a decade, causing concerns among Chinese regulators who subsequently began mandating banks to draw in credit lines in an effort to prevent the economy from overheating.

The YPO Global Pulse, which was released early February, is the only CEO economic sentiment survey to span the globe on a quarterly basis, capturing answers from more than 2,000 CEOs representing companies of all sizes around the world, including those in investment banking and financial services.