Coop is the new title sponsor of the Eliteserien, Norway's premier domestic soccer league.
As part of the three-year agreement, which has an option for a two-year extension, the retail cooperative will also be a partner of the second-tier OBOS league.
"Coop is owned by our customers and we are committed to supporting the sports that engage the population," said Coop's chief executive, Geir Inge Stokke. "Football is the national sport for both young and old and we are proud to be developing broad and top Norwegian football in the years to come."
Leif Overland, chief executive of Norwegian Professional Football League, added: "Coop and football in Norway share values like responsibility, team spirit and unity. And in the same way as football, Coop is a popular player that creates a wide engagement in all parts of the country."
After nine matches, Rosenborg top the Eliteserien, two points ahead of Odd.