Carlton United Breweries (CUB), a subsidiary of Foster's Brewing, and Lion Nathan are to appear in court today, after Foster's Brewing launched legal action against its Australian rival in a dispute over Olympic sponsorship.Foster's the official beer supplier for the Olympic games is claiming that Lion Nathan is illegally using the Olympics to market its biggest selling beer, Tooheys New.The complications have arisen because Lion Nathan is the official beer supplier to Stadium Australia, the main location for the Olympics. However, the agreement does not apply to the Olympic or the Paralympic Games.A Lion Nathan promotion says Tooheys is the "Beer choice for Stadium Australia", and the packaging features a picture of Stadium Australia.CUB, vice-president of Olympics Alan Kemp told the Australian press yesterday that the company was suing Lion Nathan under the misrepresentation provisions of the Trade Practices Act.He continued that the advertisement on the Tooheys cartons suggested the beer was available to the public at the Stadium during the Olympics.However, Lion Nathan told that it would defend the matter as it had done nothing to contravene the Trade Practices Act.It has said that the company has no intention of promoting itself as the official beer of the Stadium Australia during the Olympics.