As China's economy has grown and skyscrapers sprouted in cities extending ever westward from the Pacific coast, Otis Elevator Co. went along for the ride. But with China now in a slump and the value of its currency the most recent casualty, Otis and other manufacturing companies staking much on Asia's biggest economy now face a moment of reckoning. After saying for years that increased urbanization would propel growth in China, parent company United Technologies Corp., based in Hartford, cut its expected revenue and profit for the year, due partly to the slowdown across the Pacific. "It's tough to get this bad news out," Greg Hayes, chief executive of United Technologies, said in a call with investor analysts July 21 when second-quarter profit and revenue results were released. "The slowdown in China is worse than what we had expected." "Growth is clearly slowing in China," said John Frisbie, president of the U.S.-China Business Council. "Companies are seeing a slowdown in their revenue growth."