Chelsea Football Club said it made a pretax loss of £140 million (€204 million) for the year to end-June 2005.
The loss was almost 60 per cent bigger than the club's previous £87.8 million loss.
Chelsea said it was down to a series of exceptional one-off items, including £25.5 million arising from the termination of a contract with kit supplier Umbro and £24 million from a write-down in the value of some players, including Adrian Mutu and Juan Sebastian Veron.
"These figures reflect the continuing restructuring of the business which we began in 2003/4," chief executive Peter Kenyon said in a statement.
"The overall loss increase is, in the main, down to some exceptional items that were necessary in order to help us achieve our strategic business aim of break-even by 2009/10.
"In simple terms we have taken some pain now for long-term gain," Mr Kenyon said.