Manchester United have dropped from second to fourth in the list of the world's wealthiest clubs, trailing Real Madrid, Barcelona and Juventus.
Real Madrid and Barcelona top the league despite contrasting seasons
United headed Deloitte's Football Money League for eight years until being deposed by Real Madrid last year.
English clubs fill eight out of the top 20 spots in Deloitte's table, based on revenues generated during 2005/6.
United remain the world's most profitable club, making a £49.7m profit in the year to June 2006.
Deloitte's figures take into account income from ticket sales, merchandising and broadcasting contracts but do not include transfer revenues and does not calculate profitability.
Between them, the top 20 clubs had sales of more than £2.1bn.
Real Madrid retained its crown as the world's wealthiest club, in terms of sales, despite securing no silverware for the third consecutive year.
Its revenues rose to £202m from £186.2m the year before.
Barcelona leapfrogged Manchester United into second place, boosted by their victory in the Champions League final, while Italian club Juventus moved up one spot to third.
WORLD'S WEALTHIEST CLUBS BY REVENUE
1)Real Madrid: £202m
4)Man Utd: £167.8m
5)AC Milan: £165m
7)Inter Milan: £142.8m
8)Bayern Munich: £141.5m
Source: Deloitte: 2005/6
United dropped into fourth place after its revenues rose from £166.4m to £167.8m.
Deloitte said it believed this fall may only be temporary as further expansion of their Old Trafford ground should significantly boost the club's match day income.
"Manchester United may be in fourth position this year but with the completion of their stadium development we can expect them to move back up the list in 2006/07," said Deloitte's Paul Rawnsley.
Chelsea dropped a place to sixth despite their revenues rising to £152.8m while Arsenal, helped by their appearance in the Champions League final, jumped a place to ninth.
The other British clubs to make it into the list were Liverpool(10), Newcastle United(13), Tottenham Hotspur(15), Manchester City(17), Rangers(18) and West Ham(19).
With a lucrative new TV contract coming into effect next year, Deloitte said Premiership clubs could fill more than half of the list by 2007/8.
But Deloitte added that Spain's two footballing giants would not give up their positions at the top of the table lightly.
"The two clubs have had contrasting strategies, with Real focusing on driving commercial revenue from recruiting its Galactico players and Barcelona having a more balanced revenue portfolio," said Dan Jones, a partner in the firm's Sports Business Group.