UEFA says Europe's top soccer clubs collectively lost more than $2 billion in 2010, and their debts keep rising ahead of planned rules to sanction clubs for overspending.

UEFA analysis of around 650 clubs revealed 56 percent lost money in the 2010 financial year, and their total debt was $10.9 billion.

UEFA general secretary Gianni Infantino said it was ''a last wake-up call'' with clubs subject to UEFA's financial fair play monitoring since July 2011.

UEFA's study showed clubs' combined annual loss rose 36 percent, around $520 million, on 2009 figures.

This was despite rising revenues totaling $16.6 billion for top-tier European clubs, an increased income of 6.6 percent.