(Reuters) - Barcelona have agreed a new four-year deal for their shirt sponsorship with Japanese internet retailer Rakuten (T:4755) worth 55 million euros (47.26 million pound) a year excluding potential add-ons, La Liga champions said on Wednesday.
Barcelona -- once renowned for never having had a sponsor on their shirts -- will earn an additional 1.5 million euros for each time they win La Liga and an additional 5 million euros each time they win the Champions League.
The deal, which has an option to extend into a fifth season, will begin from the 2017-18 campaign.
Barcelona president Josep Bartomeu told reporters that the deal puts the club "at the forefront of sports club sponsorships", and will help the club "achieve its goal of being a reference point worldwide".
Five-times Champions League winners and 24-times La Liga champions Barcelona took their first steps towards ending the sponsorship-free tradition in 2006 by bearing the logo of UNICEF on their shirts while donating 1.5 million euros per year to the charity.
In December 2010, they agreed a five-year deal with the Qatar Foundation worth 30 million euros per year, at that time the most lucrative shirt sponsorship in football.
The Rakuten deal represents one of the largest for on-shirt advertising for a football club and is roughly the same amount English Premier League side Manchester United earns in its 47 million pounds-a-year contract with American car maker Chevrolet.
Barcelona are also set to outstrip United's 75 million pounds ($93.37 million) a year sportswear agreement with Adidas (DE:ADSGN) as they are reported to earn 155 million euros a season when its 10-year kit agreement with American sportswear giants Nike (NYSE:NKE) takes effect in 2018.
Barcelona, who are one of four clubs in Spain owned by its members, has also signed deals to feature the Turkish electronics brand Beko on shirtsleeves and American technology company Intel (NASDAQ:INTC) on the inside of its shirts.