Charlton Athletic plc chairman Richard Murray has revealed the club made a net loss of £9.9m in the financial year ending 30 June 2007.
The net loss for the previous season, 2005/06, was £8.1m, although turnover has increased from £35.9m to £41.9m.
There was an overall operating loss of £11.8m before player sales, which brought in £11.3m, and amortisation.
After their relegation from the Premier League, the sale of striker Darren Bent to Tottenham brought in £15.5m.
However, Bent's previous club Ipswich were entitled to a sell-on fee as part of the deal, which earned the Addicks a net fee of £12.9m.
As well as relegation, the 2006/07 season also saw Charlton go through three managers - Iain Dowie, Les Reed and Alan Pardew.
Amortisation is a financial term relating to the gradual reduction in value of an intangible asset to zero.