Manchester United has retained its top spot as the world’s richest football club, according to a new report.

Generating an income of over £172m, United occupied the top position for the eighth successive year of the Deloitte Football Rich List.

The report shows that the global top 20 are set to break the £2 billion income mark in 2005.

Based on income from the 2003/04 season, the top 20 consists entirely of European clubs, with UK clubs making up half of it.

It also includes five Italian clubs, plus two clubs from each of Germany, Scotland and Spain and one from France.

In second place glamour club Real Madrid have halved the gap between themselves and Manchester United.

Chelsea and Barcelona are the biggest climbers, up from tenth to fourth position and thirteenth to seventh position respectively.

Bayern Munich and Schalke 04 have slipped down the rich list despite the German corporate market's significant contributions to the Bundesliga clubs.

Dan Jones, partner in the Sports Business Group at Deloitte, said: "The second round of this season's Champions League draw has paired eight of our top nine Money League clubs with each other. The results of these matches may have a big influence on the clubs' position in the next Money League. Competing in the Champions League can deliver an extra ten per cent to 20 per cent for a club."

The UK clubs have a much more balanced spread of revenue than their European counterparts, the report found.

Spanish and Italian are more dependent on broadcasting largely due to their individual broadcast rights deals.

Commenting on the importance of clubs generating significant income from their stadia, Paul Rawnsley from the Sports Business Group at Deloitte, said: "In general, UK clubs have consistently managed, through focused investment and targeted marketing, to achieve enhanced returns from their stadium asset.

"Many of Europe's leading clubs have a great, and as yet relatively unexploited, opportunity to develop significant income streams from their stadia."

Mr Jones said the top clubs are increasingly looking beyond the domestic and European markets to boost their incomes.

He added: "However, gaining a fan in another country is one thing; unlocking some value in a distant and, in all likelihood, less committee fan base is not easy. The key is to have a clear long term strategy. These are not quick wins."

Top 20 rich list:

1. Manchester United: £171.5m

2. Real Madrid: £156.3m

3. AC Milan: £147.2m

4. Chelsea: £143.7m

5. Juventus £142.4m

6. Arsenal: £115m

7. Barcelona: £112m

8. Internazionale £110.3m

9. Bayern Munich: £110.1m

10. Liverpool: £92.3m

11. Newcastle United: £90.5m

12. AS Roma: £72m

13. Celtic £69m

14. Tottenham Hotspur: £66.3

15. SS Lazio £65.8

16. Manchester City: £61.9

17. Schalke 04: £60.5

18. Olympique Marseille: £58.3

19. Rangers: £57.1

20. Aston Villa: £55.9