Big Tobacco just unveiled a new strategy to stay big: Merge.

Altria and Philip Morris International said they have been in talks to reunite as smokers worldwide increasingly ditch the habit.

The two Marlboro makers — which split more than a decade ago, with Altria taking the home territory and Philip Morris taking overseas — confirmed on Tuesday that they’re in talks to recombine in an all-stock, $200 billion-plus deal.

Wall Street recoiled at the news amid reports that the deal had no premium, with some analysts questioning its rationale. Shares of Philip Morris plunged 7.7 percent while Altria fell 4 percent after climbing as much as 10 percent after the talks were confirmed.

Still, some industry watchers said the merger could give Altria and Philip Morris a boost as e-cigarettes increasingly lure nicotine fiends away from combustible smokes.

Altria, which shelled out $12.8 billion last year for a 35-percent stake in Juul, could accelerate distribution of the controversial vaping device abroad with the help of Philip Morris.

Likewise, Philip Morris has poured $6 billion into IQOS, a gadget that heats tobacco to produce nicotine vapor without burning it, and which got approval from the US Food and Drug Administration in April. Currently sold in the UK and Japan, it’s slated to hit the US next month.

“We believe a Philip Morris-Altria merger would create the leading global nicotine company,” Bonnie Herzog, analyst at Wells Fargo Securities, said in a note Tuesday.

A merger would allow for an “improved and potentially accelerated rollout of IQOS and Juul globally,” Herzog said.

Cigarette sales industrywide slumped 4.5 percent last year on an adjusted basis, according to analysts at Cowen. Meanwhile, the e-cigarette market, worth about $11 billion in 2018, is expected to grow at more than 8 percent annually over the next five years, according to Mordor Intelligence.

Altria and Philip Morris, which split more than a decade ago amid concerns about a US regulatory crackdown confirmed Tuesday that they have been discussing an “all-stock, merger of equals” while warning that there is no guarantee a deal will be agreed upon or even completed.

“Any transaction would be subject to the approval of the two companies’ boards and shareholders, and regulators, as well as other conditions,” Philip Morris and Altria said in their respective statements Tuesday.

With Post wires