iHeartMedia Inc. agreed to invest up to $10 million in the publisher of High Times, the 44-year-old marijuana magazine, offering the biggest U.S. radio broadcaster access to the nation’s growing number of cannabis consumers.

The deal, which at current valuation would give iHeart US:IHRTQ about a 5% stake in Hightimes Holding Corp., provides the publisher with access to the media giant’s radio and outdoor advertising as it gears up to sell shares to the public. High Times is expected to announce the investment in a filing with Securities and Exchange Commission.