The combined revenues of the world's 20 highest-earning football clubs increased by 3 per cent to more than EUR4.4bn (GBP3.7bn, USD5.8bn), according to new research from Deloitte.

According to the Deloitte Football Money League, the top 20 clubs account for more than a quarter of the European market. Nine clubs recorded double-digit growth for the period.

German club Schalke 04 was the highest climber during 2010-11, moving up six places and into the top 10 for the first time. Napoli (Italy) makes its first ever appearance in the top 20.

All but one of the top 20 clubs played in European competition during the 2010-11 season, with Real Madrid and Barcelona (Spain) continuing to lead the Money League.

Dan Jones, partner in Deloitte's Sports Business Group, said: "Continued growth of the top 20 clubs during 2010-11 emphasises the strength of football's top clubs, especially in these tough economic times.

"Ability to drive strong broadcast audiences and continuing attraction to corporate partners has made them relatively resilient to the economic downturn."

Details: www.deloitte.com

Image: Real Madrid of Spain topped the Money League once again