Israel-based Teva, the world's largest generic drugmaker, for the past five years has been hit hard by a weak U.S. generics market and stiff competition from competition to its blockbuster multiple sclerosis drug Copaxone.

After years of negotiations, Teva on Tuesday proposed a $4.35 billion nationwide settlement - mostly cash and partly medicines - to resolve its opioid lawsuits.

The agreement in principle should take a few weeks to finalize and then it needs a host of approvals before it takes effect, chief executive Kare Schultz said on Wednesday.

He said that under terms of the agreement, it will cost the company between $300 million and $400 million over 13 years - a sum shareholders deem as a relief given its New York-listed shares are up 20% in early trade.

The deal "is the beginning of putting this behind us," Schultz told a conference call of analysts.

"We have a very sustainable foundation, which means that we can return to growth in both our revenue and earnings," he said, adding that growth in the coming years would be driven by its biosimilar products, along with its migraine drug Ajovy and Huntington's disease treatment Austedo.

Schultz said that nearly $200 billion of drugs will be coming off patent in the next five years and $400 billion in the next decade. Teva, he said, has 1,100 products ongoing to cover some 80% of those.

(Reporting by Steven Scheer; Editing by Jan Harvey and Angus MacSwan)

By Steven Scheer