* Judge says antitrust claims already addressed
* MGA accused Mattel of trying to litigate it to death
* Mattel appealing $310 million award to MGA over Bratz
By Jonathan Stempel and Dhanya Skariachan
Feb 22 (Reuters) - Mattel Inc has won the dismissal of an antitrust lawsuit brought by bitter rival MGA Entertainment Inc that accused the toy giant of trying to monopolize the U.S. market for fashion dolls.
U.S. District Judge David Carter in Los Angeles on Tuesday threw out the case more than six months after separately awarding MGA roughly $310 million in damages, attorney's fees and other costs in a long battle over who owned rights to the once billion-dollar Bratz doll line.
Carter's decision in the antitrust case does not disturb his Aug. 4, 2011 ruling, which followed a jury trial and which Mattel is appealing.
In alleging violations of the Sherman antitrust law, MGA had charged that the earlier litigation was part of Mattel's costly strategy to "litigate MGA to death" and ensure it could maintain a dominant market share in fashion dolls.
But Carter said MGA essentially raised its antitrust claims in the Bratz litigation, and that its allegations that Mattel's violations were continuing were not supported by facts.
"MGA's current and prior claims are the same," and the law "bars a later claim that is based on allegations of misconduct of which the claimant was previously aware and had alleged in the prior case," Carter wrote. He dismissed the case with prejudice, meaning MGA cannot bring it again.
Isaac Larian, MGA's chief executive, said his company plans to appeal. "The judge dismissed on a technicality," Larian said in a statement. "We will pursue Mattel accordingly until they stop their monopolistic behavior."
Mattel spokesman Alan Hilowitz said the company is pleased with the decision.
MGA is based in Van Nuys, California, and Mattel in El Segundo, California.
The legal battle began in April 2004, when Mattel accused MGA of copyright violations over the multi-ethnic Bratz line after former Barbie designer and Bratz creator Carter Bryant had jumped to MGA.
A jury awarded Mattel $100 million in 2008, but a federal appeals court overturned that award in 2010. MGA then prevailed in a retrial.
In afternoon trading, Mattel shares were up 2 cents at $32.04 on Nasdaq.
The case is MGA Entertainment Inc v. Mattel Inc et al, U.S. District Court, Central District of California, No. 11-01063.