Premier League clubs\' revenues smashed through the £2 billion barrier for the first time last year but soaring wages remain a concern for the world\'s richest league, a study reported on Thursday. The 20th Annual Review of Football Finance from Deloitte reported that Premier League clubs earned £2.030 million in 2009/10, a figure which is expected to rise to £2.2 billion in 2010/2011 when new television deals kick in. However the report cautioned that the increase in revenues of £49 million was outstripped by the rise in total wage costs of £64 million, taking total payroll costs to more than £1.4 billion or 68 percent of revenues. Chelsea were the the club with the biggest wage bill (£174 million) followed by Manchester City (£133 million), who nosed ahead of city rivals Manchester United who spent £132 million. However City\'s mammoth wages represented 107 percent of the club\'s revenue, compared to United, whose wages-to-revenue ratio came in at 46 percent. City\'s spiralling wage costs represent a challenge for the club ahead of the introduction of UEFA\'s Financial Fair Play rules, which will seek to make clubs participating in European competition to break even by 2011-2012. \"Cost control remains the biggest challenge facing clubs, at all levels of the professional football pyramid,\" Paul Rawnsley, Director in the Sports Business Group at Deloitte said. Nevertheless Rawnsley believed English Premier League clubs would be able to make the transition to UEFA\'s financial regulations given the league standing as the most lucrative in world football. \"Premier League clubs should be well placed to comply with UEFA’s regulations, as the Premier League remains the top revenue generating league in Europe,\" Rawnsley said. \"Clubs have time to make adjustments to their business plans before the new regulations are effective, as well as increased broadcast revenue from 2010/11 to help deliver a better balance between spending on players and revenue generation.\" The Premier League revenue of £2 billion far exceeded any other European league, leading from Germany (£1.4 billion), Spain and Italy (£1.3 billion each) and France (£0.9 billion). Meanwhile the imbalance between wages and revenue was even more pronounced in English football\'s second tier, the Championship, with a wages/revenue ratio of 88 percent. Other figures in the report showed record pre-tax losses in the Premier League clubs of £445 million overall, with gross transfer spending down by more than 20 percent from the record £713 million in 2008-09 to £559 million last season. However net debt in Premier League clubs fell by 20 percent from £3.3 billion to £2.6 billion, figures attributed to debt to equity conversions and Arsenal\'s successful selling off property in their Highbury Square development.