Teva Pharmaceutical Industries, the world's biggest generic drugmaker, forecast a big drop in profit in 2014 if cheap generic competition to its blockbuster multiple sclerosis treatment Copaxone is launched.

Israel-based Teva provided on Tuesday two sets of forecasts for next year - one assuming the launch of at least two generic competitors to Copaxone in the United States on June 1, 2014, and the other assuming no U.S. generic competition in 2014.

Assuming Copaxone does face competition, Teva estimates it will earn $4.20 to $4.50 a share on an adjusted basis on revenue of $19.3 billion to $20.3 billion. Without competition, Teva projects earnings of $4.80-$5.10 a share on revenue of $19.8 billion to $20.8 billion.

Analysts forecast the company would earn $4.94 a share on revenue of $20 billion in 2014, according to Thomson Reuters I/B/E/S. In 2013, analysts project Teva will earn $4.99 per share on revenue of $20.1 billion.

A U.S. Supreme Court justice last month declined a request from Teva for a stay of an appeals court ruling that would strip the company's $4 billion-a-year Copaxone of patent protection in 2014, rather than 2015.

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

Teva estimated that each month of delay in the launch of generic competitors to Copaxone in the United States will contribute $78 million to revenue and 8 cents to adjusted EPS.

"2014 will be a pivotal year for Teva and a year of major transitions across the company," said Eyal Desheh, acting chief executive of Teva.

The former finance head took over as CEO on an interim basis following the abrupt departure of Jeremy Levin at the end of October, after a clash with Chairman Phillip Frost that left the company's direction and decision-making process in doubt.

Teva has announced plans to cut 5,000 jobs, or 10 percent of its workforce, as it prepares for competition to Copaxone.

Teva said its forecasts assume the launch in early 2014 of a longer-lasting version of the MS drug that would be injected three times a week, with the company aiming to move patients taking its current daily drug to the new offering.