Nielsen Holdings, the American market research company that owns the Outdoor Retailer show and other properties, plans to go public on the New York Stock Exchange by selling a 20 percent share for $1.57 billion. It would also offer $250 million in convertible bonds. The company's net revenues rose at a compound annual average rate of 5.7 percent recently. They reached $4.8 billion last year, with an Ebitda ratio of 27.3 percent. Nielsen Expositions made an operating profit of $55 million on revenues of $150 million in the nine months ended last Sept. 30. This subsidiary has shut down ots Fly Fishing and Action Sports Retailer shows in the U.S. and sold its 50 percent stake in VNU Exhibitions Europe.