John Feehan, Chief Executive of the Six Nations Council, said: "RBS has been a hugely supportive sponsor for the championship and rugby as a whole and we are delighted that we have extended our association.
"RBS's title sponsorship of the Six Nations Championship represents an important contribution for each of our six constituent Unions and Federations, which ultimately contributes to funding and developing the sport of rugby union at all levels in those territories.
"This plays a very important part in ensuring the stability and health of the sport in the Northern Hemisphere."
Allan Watt, RBS Head of Group Brand Communications, said: "Our association with the Six Nations has created benefits for both the sport of rugby and RBS.
"We began discussions with the Six Nations Council about the renewal of the title sponsorship before last year's tournament and reached an agreement in May 2008 to extend through to 2013.
"The RBS 6 Nations has been selected to meet very specific business objectives within the six competing nations.
"In 2009, our focus will be on linking the RBS 6 Nations and rugby in the communities which we operate in.
"New for this year, RBS RugbyLink will be a series of club, school and charity initiatives connecting fans with rugby while 'The Hub' gives a chance for all our customers to win match tickets and rugby-related prizes."