By Peter Burrows & Olga Kharif - 2013-03-04T10:45:13Z While Tim Cook has dropped hints that Apple Inc. (AAPL) is hard at work on a television to drive the next era of growth, the company’s wristwatch-style device, still in development, may prove more profitable. The global watch industry will generate more than $60 billion in sales in 2013, said Citigroup Inc. analyst Oliver Chen. While that’s smaller than the pool of revenue that comes from TVs, gross margins on watches are about 60 percent, he said. That’s four times bigger than for televisions,