Tobacco companies Philip Morris International and Altria are in merger talks.

The deal would reunite the two companies, which separated in 2008 to focus on international and domestic markets, respectively.

Phillip Morris said that there is “no assurance that any agreement or transaction will result from these discussions.”

However, a merger of the two would create a company with market value of more than $200 billion, Reuters estimated. And the companies are already partnering on the U.S. launch of a heat-not-burn cigarette alternative, iQOS, made by Philip Morris.

Altria acquired a 35% stake in e-cigarette manufacturer Juul, helping to offset declining cigarette sales. Earlier this year Altria executives estimated annual U.S. cigarette volumes would decline between 4% and 6% through 2023.