The Vodafone Group has warned that its revenue growth will slow down next fiscal year, an Associated Press report said.
The report also quoted a Vodafone report as saying that its assets were overvalued by as much as 28 billion pounds ($49 billion).
The report further said shares in the mobile phone company fell 2.8% to close at $1.99 after it said it would take an impairment charge of between 23 billion pounds ($40.2 billion) and 28 billion pounds ($49 billion).
The company also said operations in Italy and possibly Japan were also overvalued.
Vodafone said increasing competition would result in revenue growth slowing to 5% to 6.5% in the fiscal year ending in March 2007, compared to forecasts of 6% to 9% for fiscal 2006.
It said it was issuing the warning, its third in four months, against "intensifying competition and pricing pressures" in several of its key markets, including Europe.
EBITDA are now expected to fall by 1% in 2007, the company said.
This year would be unaffected, however, it added.