The Bulgarian government put its 36-percent stake in Arsenal Kazanlak, the country's largest arms and munitions production plant, up for sale on Friday, the privatisation agency said in a statement.
The government's 35.78 percent stake was offered to buyers with experience in the defence or export sectors, with binding bids to be submitted within the next four months.
Arsenal is Bulgaria's biggest arms and munitions manufacturer and was a licenced producer of Russian Kalashnikov assault rifles during the Cold War.
In recent years, however, the licences have been a constant bone of contention between Sofia and Moscow which has accused Bulgaria of counterfeiting the famous AK-47.
Its plant, employing over 5,000 workers, was partly privatised through management and employee buyouts between 1999 and 2001.
About 65 percent is now owned by the private Arsenal 2000 joint-stock company, cited in the Bulgarian media as the most likely buyer of the remaining government stake.