Producer Sue Vertue confirmed at the Edinburgh International Television Festival that the hit BBC drama - starring Benedict Cumberbatch and Martin Freeman - will resume filming in January.
Vertue added that the new episodes will then debut on UK television in the latter half of 2013, with August earmarked as a possible air date.
Sherlock co-creators Steven Moffat and Mark Gatiss also revealed three teaser words for the new trilogy of episodes - 'Rat', 'Wedding' and 'Bow'.
Meanwhile, Andrew Scott - who was also in attendance at the show's panel - refused to confirm if he would reprise his role as the villainous Moriarty.
"Moriarty is dead," he replied with a smile, when asked if his character could return.
Watch Mark Gatiss and Benedict Cumberbatch discuss the third series of Sherlock with Digital Spy below: