Teva Pharmaceutical Industries on Monday asked the U.S. Supreme Court to stay an appeals court ruling that would strip its $4 billion-a-year multiple sclerosis drug Copaxone of its patent protection in 2014 rather than 2015.

In July, the U.S. Court of Appeals for the Federal Circuit issued its decision in a patent fight that pits Teva against two teams developing cheaper generic forms of Copaxone: one with Novartis AG and Momenta Pharmaceuticals Inc and another between Mylan Inc and Natco Pharma Ltd .

The appeals court upheld some of nine patents involved in the drug, or portions thereof, but declared several invalid, shortening patent protection for the drug.

Last week the appeals court subsequently declined to reconsider its ruling and refused to issue a stay.

Teva lawyers on Monday asked the Supreme Court to impose a stay while they prepare their appeal of the July ruling.

They said in their application that the company would likely face "irreparable harm" if the appeals court ruling is allowed to go into effect. That's because generic rivals would be able to go to market in May 2014 instead of a year later.

The high court has yet to respond to the request.