Barcelona have agreed a record shirt sponsorship deal with the Qatar Foundation worth 30 million euros ($40 million) a season through to the end of the 2015-16 campaign, the La Liga champions said on Friday.
The deal is the biggest for any soccer club, the Spanish champions said on their website, and will net the Catalan side as much as 170 million euros.
The total includes 15 million euros for commercial rights for the current season and a bonus for winning titles that could be as much as 5 million, Barca added.
The Qatar Foundation, founded by Sheikh Hamad Bin Khalifa Al Thani, the Emir of Qatar, in 1995, has projects focusing on education, scientific research and community development. It is also engaged in several corporate joint ventures.
Last week the tiny Gulf state was chosen by soccer's governing body FIFA to host the World Cup in 2022, when it will become the first Arab country to stage the finals, and Barca coach Pep Guardiola was one of the ambassadors for the bid.
The club are one of the few in world soccer not to have a corporate logo on their first-team shirts, instead displaying the name of the United Nations Children's Fund, UNICEF, for which they pay the organisation 1.5 million euros a year.
Under the agreement announced on Friday, marketing experts will seek to find a way for both logos to be displayed, although if that was not possible the UNICEF name would be moved to another part of the shirt, a club spokesman said.
"With this accord, Barca becomes the undisputed brand leader in world football, far ahead of international rivals," Javier Faus, a club vice president, told a news conference.
The agreement also includes a commitment for Barca to play one friendly per season, not necessarily in Qatar, and the Qatar Foundation will take part in joint projects with UNICEF and the club's own foundation.
A study by consulting firm Sport+Markt published in October showed new deals for English Premier League clubs Manchester United and Liverpool, with insurance brokerage AON and bank Standard Chartered respectively, were the two most valuable contracts in 2010/11 at 23.6 million euros each.
Real Madrid's 23-million-euro deal with Internet bookmaker bwin was the next biggest.