The maker of Marlboro cigarettes has held early talks to buy the Canadian marijuana company Cronos in what would be the first major takeover of a pot producer by a big tobacco group, according to people briefed on the discussions.

A takeover of Cronos by Altria amid spreading decriminalisation would rank among the largest investments in the budding pot industry. Shares in Cronos, which grows and distributes cannabis, climbed 14 per cent in New York on Monday to $10.39, giving the Canadian company a market capitalisation of $1.9bn.