HONG KONG - The gloom battering the U.S. and European economies is increasingly dragging down Asia, the world's global growth engine. South Korea propped up its economy Thursday with an unexpected interest rate cut, and the odds of a similar move in Australia rose after figures showed a weaker-than-expected job market. In Japan, the central bank trimmed its outlook for growth. China, which dominates the region, is expected to release data Friday that will show a further slowdown in its giant economy. Combined, the events crystallize the sense that the Asia-Pacific region is increasingly vulnerable to economic chills elsewhere. "We are worried about Asia," said Rob Subbaraman, an economist at Nomura in Hong Kong. The slowdown so far has been moderate, but there is a real sense that Asia is teetering, that it could reach a tipping point where the slowdown accelerates, and companies really start to cut down on capital expenditures and hiring. We're not there yet, but we are edging closer to that point. The Asian Development Bank echoed that sentiment Thursday, when it lowered its 2012 forecast for economic growth in developing Asian countries - a group that includes India and Thailand - to 6.6 percent from 6.9 percent. For next year, the bank now projects 7.1 percent growth, rather than the 7.3 percent it had forecast in April. "Slower growth in the U.S. and euro area reduced demand for the region's exports," the bank noted in a report. Worries over the economic strength of important developing economies have also emerged recently. Over the past five years, hypercompetitive Asia has withstood with relative health the U.S. mortgage crisis and then the European debt crisis. So far, the weakness across the region is far less pronounced than the aftermath of the collapse of Lehman Brothers in 2008. The question for many policy makers, economists and businesses: Will it remain that way? The drawn-out debt woes and austerity measures in Europe and the lethargic pace of growth in the United States have affected Asia and many other emerging-market economies directly by undermining demand for exports. Asia, in particular China, is the world's factory, and exports remain an important driver for many Asian economies. Numerous Asian companies have reported disappointing earnings and outlooks in recent weeks, with the Indian information technology giant Infosys joining that list Thursday, lowering its sales forecast for the current financial year. Infosys" shares closed down 8.4 percent. On the policy front, central bankers and officials also appear increasingly concerned about the slowing momentum in growth and have begun to follow the West with efforts to bolster growth. In South Korea, the central bank lowered its key base rate on Thursday to 3 percent from 3.25 percent. It was the first cut by the bank in more than three years and came as a surprise to economists, most of whom had expected the bank to keep interest rates unchanged. The Bank of Korea cited the global environment for its move. Some economic indicators in the United States "have shown signs of deteriorating, and the sluggishness of economic activities in the euro area" has "deepened," the central bank noted in a statement. Elsewhere in the region, the Japanese central bank left its key interest rate unchanged at the already low level of 0.1 percent Thursday, but in a regular review of its economic forecast, it trimmed its outlook for the year ending next March to a growth rate of 2.2 percent, from an earlier projection of 2.3 percent. "There is still a lot of uncertainty about the fiscal and structural reforms that Europe needs," Masaaki Shirakawa, the central bank governor, said, according to Reuters. Europe remains the risk factor that we have to watch out for the most. And in Australia, employment fell by 27,000 in June, and the unemployment rate edged up to 5.2 percent from 5.1 percent in May. That is a low rate compared with that in the United States and Europe, but the unexpectedly weak outcome raised the likelihood that the central bank might lower interest rates again in coming months.