Real Madrid and Barcelona are the world's two most valuable soccer clubs, which marks the first time Spain's signature clubs have grabbed the top two spots since Forbes began ranking teams a decade ago.

During the 2012-13 season Real Madrid generated revenue of $675 million–the most of any team in history in any sport–and are now worth $3.44 billion, 4% more than a year ago. Barcelona posted the second-most revenue ($627 million) and are worth $3.2 billion, up 23% from last year.

Manchester United is the third most valuable club in the world, worth $2.8 billion. But the value of the club decreased by 11% during the past year after a disappointing performance in the Premier League.

Bayern Munich rose 41% in value to $1.85 billion and now rank fourth.

Arsenal, Chelsea, Manchester City, AC Milan, Juventus and Liverpool round out the top-10.

Two newcomers to the top-20: Paris Saint-German landed in the 15th spot, worth $415 million and Galatasaray, worth $347 million, ranked 16th.