(CNN) -- Businesses may still be suffering from the effects of widespread economic downturn, but the world's leading football clubs are earning more than ever according to a new report.
The top-20 teams generated a record €4.3 billion ($5.9 billion) in the 2009-10 season, an 8% increase on the previous period, says financial advisor Deloitte.
Its Football Money League, released on Thursday, revealed that Spanish clubs Real Madrid and Barcelona remained top of the earnings table ahead of England's Manchester United and Germany's Bayern Munich.
"All bar three of the top-20 clubs achieved revenue growth during 2009-10, demonstrating the continued resilience of football's top clubs as the full impact of the global economic downturn took hold," Deloitte's Dan Jones said.
"The game's top clubs have proved themselves well-placed to meet these economic challenges given their large and loyal supporter bases, ability to drive broadcast audiences, and continuing attraction to corporate partners."
Real's income rose to €438.6 million ($601 million) despite not winning a trophy following the world-record $130 million signing of Cristiano Ronaldo and the $92 million capture of Kaka.
Barcelona, who won the Spanish title and reached the Champions League semifinals, will soon become the second team to top €400 million in revenue -- according to Jones -- following its decision to accept paid shirt sponsorship.
The Catalan club generated €398 million ($546 million) last season, an increase of almost €33 million ($45 million).
"The club has now entered into its first paid-for, multi-year shirtfront sponsorship deal, for a guaranteed minimum of €165 million over the duration of the contract, a new world record," Jones said.
"We expect the battle for top spot in the Money League to be between Spain's two superclubs for the next few years at least."
The top-six was unchanged, with United's Premier League rivals Arsenal and Chelsea rounding it out.
AC Milan moved up to seventh, giving Italy three clubs in the top-10 ahead of city rivals Inter and Juventus.
Revealing a huge gap in Spanish clubs' spending power, Atletico Madrid was the World Cup-winning nation's only other entry at 17th.
England, by contrast, had seven clubs including Liverpool in eighth and Manchester City -- rising nine places to 11th.
Italy and Germany both had four entries -- the latter country seeing Werder Bremen and current league leaders Borussia Dortmund drop out -- with France's Lyon and Marseille 14th and 15th respectively.