Marijuana pioneer Uruguay said on Thursday it had granted licenses to two companies to grow the plant for commercial distribution, adding that the pot should go on sale in pharmacies next year.

The South American country was the world's first to legalize the cultivation and distribution of marijuana, aiming to wrest control of the trade from drug gangs while regulating and even taxing its consumption.

But the novelty of the endeavor has thrown up challenges preventing the government from meeting its own deadlines in implementing legislation passed nearly two years ago. The country originally planned to distribute licenses a year ago.