U.S. industrial conglomerate General Electric will take a $6.2 billion charge in its fourth-quarter results for a more than decade-old insurance portfolio covering long-term healthcare costs, the company said on Tuesday.

GE, whose shares sank 3.7 percent in premarket on the news, said the charge would rise to $7.5 billion when adjusted for Congress' newly-passed cut in corporate tax rates to 21 percent.