The renewed deal is the longest in Premiership Rugby history and gives BT live broadcast rights for up to 80 live matches per season as well as extended highlights for all 135 Aviva Premiership Rugby matches per season from 2015-16.
They also get live broadcast rights to the entire Singha Premiership Rugby 7s Series and midweek review and preview programming.
Mark McCafferty, the chief executive of Premiership Rugby, said: “BT Sport has been a fantastic partner for English club rugby so we are delighted that we have been able to extend our relationship with them for a further four years. This is the longest TV agreement in the history of Premiership Rugby.
“In the 18 months we have been on-air with them our live TV audiences have grown by 50 per cent so it is clear that the partnership is going from strength to strength.
“In almost two seasons of coverage broadcasting the Aviva Premiership BT Sport has set new standards for the live broadcast of rugby. Their innovative style has received great acclaim and we look forward to developing the partnership over the next six seasons.”
John Petter, chief executive, BT Consumer, said: “We are absolutely delighted to be extending our partnership with Premiership Rugby. 2015 will be an amazing year for rugby in the UK and the popularity of rugby will continue to grow.
“We’re delighted to be a part of this and that our customers can look forward to another six seasons of the Aviva Premiership on BT Sport.”
BT says it will also work with Premiership Rugby to develop a community rugby programme and continue to market top flight English club rugby.
McCafferty added: “This partnership is about far more that what is seen on our TV screens. BT Sport is committed to Premiership Rugby and they will help us to grow the game in England.”