Sunbeam had accused the research firm of abusing its dominant market position by introducing a new audience measurement system, alleged flaws in which led to an undercounting of the audience for Sunbeam’s Miami TV channel WSVN, costing it ad revenue.

The court ruled last week that Sunbeam’s anti-trust claims fell short in establishing the existence of a “willing and able” competitor who had been excluded from competing against Nielsen. It had also failed to show that WSVN’s current ratings were less accurate than they would be under a competitor’s methodology, the court said.

In dismissing the claims Judge Paul Huck noted that “there is evidence of exclusionary contracting practices”. He deferred ruling on two remaining counts – breach of contract and violation of Florida’s Deceptive and Unfair Trade Practices Act – until a supplementary briefing is submitted and considered later this month.

The legal dispute has been rumbling on since May 2009. Recently the two sides looked close to agreeing a settlement.