Jamen Shively spent six years working at Microsoft, where he served as corporate strategy manager before leaving the company in 2009. Now, he's set his sights on an entirely different industry — legal marijuana.

This week, Shively announced plans to create the first national brand of retail marijuana for both medical and recreational users. As Reuters reports, Shively has already acquired a Washington-based company that operates two Seattle medical marijuana dispensaries, and is close to purchasing others in California and Colorado. He's also calling for the US government to legalize weed trade with Mexico, underscoring the bold (and perhaps unrealistic) scope of his vision.

Shively outlined his plans at a Seattle press conference Thursday, held alongside former Mexican president Vicente Fox. Fox and Shively are pushing for an agreement that would regulate marijuana trade between Mexico and the US, though they acknowledge that the proposal faces significant hurdles. Despite being legalized for recreational use in Washington and Colorado, pot remains illegal under US federal law, as well as international trade rules.

Shively, 45, says he has no concrete plans for overcoming these hurdles, though he seems confident that he will. "I don’t know how exactly that would be done, but I know it’s been done in other industries," he told the Seattle Times.

He also noted that he is only interested in purchasing dispensaries that are in full compliance with local and state laws, arguing that a corporation this ambitious would be too large to take risks. But experts say Shively's plan is exactly the kind of venture federal authorities are hoping to stamp out.

"A giant market in search of a brand."

"Having a national chain of marijuana-based companies is not only explicitly counter to the existing prohibition, but also counter to the government’s expressed concern about business growing too large," Alison Holcomb, author of Washington's marijuana law, told the Seattle Times.

Shively, however, seems undeterred in his quest to conquer the world of weed, which he describes as "a giant market in search of a brand." According to the Times, Shively began using marijuana about 18 months ago, and has become something of an evangelist ever since. He says he's "fallen in love with the plant," and named his Seattle-based company Diego Pellicer in honor of his great grandfather, who produced hemp.

The dream, Shively says, is to one day control 40 percent of the global marijuana market — and, of course, to reap profits along the way. "Let’s go big or go home," he said. "We're going to mint more millionaires than Microsoft with this business."