ZURICH (Reuters) - Novartis on Monday said claims of price fixing against its Sandoz generics unit amid a U.S. probe of 20 drugmakers are without merit, with the Swiss company vowing to fight allegations in a lawsuit filed last week.

"We believe that these claims are without merit and will vigorously contest them," Novartis said. "Sandoz takes its obligations under the antitrust laws seriously. We will continue to be committed to providing high-quality, affordable medicines to U.S. patients, and conducting business with customers and the government with integrity."

The 500-page lawsuit, filed by U.S. states on Friday, contends drugmakers conspired to inflate drug prices, sometimes by more than 1,000% or more, as well as stifle competition.

(Reporting by John Miller; Editing by Michael Shields)