A private equity firm with $15 billion in assets, Onex Corp., is acquiring Nielsen Expositions for $950 million in cash. The U.S. company operates more than 65 trade shows and conferences every year, including Interbike, the Health + Fitness Expo and the Outdoor Retailer Winter and Summer Markets. Owned by Nielsen Holdings, Nielsen Expositions generated operating income before amortization of $97 million on revenues of $183 million in 2012. With this move, Nielsen is focusing more on market research and other parts of its core business.