Deferred losses reduced the corporate tax base in Hungary by HUF 543bn last year, business portal gazdasag.hu said.
The size of the reduction was up from HUF 368bn in 2009 and set a new record. The big increase could be a result of the crisis or of looser rules on deferred loses introduced in 2010.
Under the new rules, companies may defer losses over an indefinite period of time, and they have no obligation to report the losses to the tax office.
Hungary's government earlier announced plans to make these rules stricter.
Hungary's corporate tax rate is 16%, but companies with a tax base under HUF 500m pay just 10%.