RBS, as principle partner of Scottish Rugby, will be a partner on all aspects of the game in Scotland, including the governing body's community activity, grassroots initiatives, domestic league and cup competitions and Scotland's age-grade and national teams.
Scottish Rugby also announced today that the Murray Group have extended their sponsorship of the Scotland national team.
The deal, previously due to conclude at the end of November after the EMC Autumn Tests, has been extended to March 31, 2011, after the forthcoming RBS 6 Nations.
Announcing the deals, Scottish Rugby chief executive Gordon McKie said: "We are delighted to have secured RBS as our principal partner for Scottish Rugby.
"We are focused on growing our sport at all levels and this integrated partnership with RBS will enable us to build upon our growth plans across the game.
"With the Scotland national team achieving success on the park (currently ranked seventh in the world) and a significant number of people taking up rugby across Scotland, the sport is in great shape.
"Attracting such a high profile brand is testimony to the hard work undertaken by all those involved in the game."
The Murray Group have been valued supporters of Scottish Rugby for the past three years.
McKie added: "Sir David Murray and the Murray Group have been, and continue to be, great supporters of Scottish Rugby.
"Their significant investment in the game in Scotland has enabled Scottish Rugby and the rugby community to develop both on and off the park.
"I'd like to thank Sir David and the Murray Group for agreeing to extend their relationship and continuing to back Scottish Rugby."