The BT Sport logo will be displayed on the front of both clubs’ shirts until 2017.
In addition, the deal will see BT Group and BT Sport promoted at Scotstoun Stadium and Murrayfield Stadium.
News of the sponsorship agreement comes just days before the BT Sport channels launch on August 1st.
The clubs’ games are broadcast on Sky Sports, meaning the satellite giant will have to feature its BT’s branding and adverts despite refusing to sell ad break slots to its rival.
Earlier this year Sky said BT could advertise its sports channels on any of Sky channel except Sky Sports. That decision was ultimately backed by media regulator Ofcom which ruled Sky was entitled to protect its own investmnet in sports programming.
Announcing the deal, BT TV boss Marc Watson, said: “We are very pleased to invest in Scottish Rugby with this sponsorship, which allows BT and BT Sport to demonstrate a commitment to supporting the game north of the border. This is part of our long term commitment to rugby, where we see great growth potential in the coming years.
“BT Sport will be the home of the Aviva Premiership, showing all 69 live games and live action from the JP Morgan Sevens. We will also be showing live coverage of the French Top 14 competition.”
Mark Dodson, chief executive of Scottish Rugby, added: “We’re absolutely delighted to have BT and BT Sport on board for the next four years. This partnership has been many months in the making and it’s been gratifying to have concluded it ahead of the BT Sport channels launching.”
BT Sport will show all 69 live games from the Aviva Premiership for four years starting with the 2013/14 season. It will also show the JP Morgan Asset Management Sevens for four years, as well as two live matches a week from the French Top 14 league.
Live coverage will be presented by Craig Doyle who will be joined by ex-England internationals Matt Dawson, Ben Kay and Austin Healey as expert pundits.
In addition, the BT Sport has signed former England captain and British and Irish Lions star Lawrence Dallaglio as its rugby expert.
