The 2006/07 season saw match attendances increase by 15.7% whilst television audience figures grew with BBC Wales and S4C recording a rise of 16.3% in their viewing figures.
Maurice Breen, Marketing Director, Wm Magner, said: "We are delighted to be continuing our sponsorship of the Magners League until 2009. Our first season as tournament sponsor saw the popularity of the Magners League increase on all levels and we are committed to working closely with Celtic Rugby to support their ambitions for the growth and development of the competition.
"The Magners League has enormous amounts of potential and continues to showcase a fantastic brand of high quality rugby. We are excited about achieving even more with our sponsorship over the next couple of years."
David Jordan, Director of Celtic Rugby, added: "We are fortunate in having such an enthusiastic sponsor as Magners Irish Cider and are pleased that they have agreed to extend their association with Celtic Rugby for another season. On the playing field we have seen that the quest for the Magners League title is very competitive - the equivalent of just two bonus point wins separated the top six teams, or over half the League, at the end of last season.
"The quality of the international players appearing in the Magners League make for an exciting and competitive tournament, the attraction of which is highlighted by our ever increasing fan base."
Magners will continue to show its commitment to the success of the Magners League with proactive and targeted activation plans which will include the continuation of broadcast sponsorships with S4C and Setanta and an advertising campaign designed to showcase the strong brand links between Magners Irish Cider and the Magners League.