Oct 9 (Reuters) - GSK has agreed to pay up to

$2.2 billion to settle most pending U.S. state court lawsuits

claiming that a discontinued version of the heartburn drug

Zantac caused cancer, the company announced on Wednesday.

The settlement with ten plaintiffs' law firms resolves about

80,000 cases, or 93% of pending cases nationwide, the company

said. It did not admit wrongdoing as part of the deal.

The litigation began after the U.S. Food and Drug

Administration in 2020 asked manufacturers to pull Zantac drug

off the market over concerns that its active ingredient,

ranitidine, could degrade into NDMA, a carcinogen, over time or

when exposed to heat.

First approved by U.S. regulators in 1983, Zantac became the

world's best-selling medicine in 1988 and one of the first to

top $1 billion in annual sales.

A drug currently sold under the name Zantac uses a different

active ingredient and contains no ranitidine.