Delays to productions at Pinewood Shepperton could cost the film studios in Buckinghamshire profits this year.
Pinewood hosted production of The Bourne Ultimatum this year
Pinewood, which hosted production of The Bourne Ultimatum this year, saw a 39% increase in pre-tax profits in the first half of the year.
However, the firm said films entering production later than expected would leave revenues down in 2007 unless deferred productions could be replaced.
Shares were 2% lower as the warning overshadowed the £2.9m pre-tax profit.
Revenues had been boosted by a return to major productions like Casino Royale and pre-tax profit was £7.16m in the year to 31 December, from £571,000 in 2005, and the firm said a decision to move into television production had also swelled its profits.
The Weakest Link, The IT Crowd and Bremner Bird and Fortune were produced in the period alongside blockbuster film Harry Potter and the Order of the Phoenix.
First-half television revenues also fell, by 15%, due to "timing differences", Pinewood said.
Despite the announcement, Pinewood said there was an "increasing interest" in film production activity after the government's new film tax credits, aimed at capturing international film makers, were introduced in January.
The firm said uncertainty remained however over the level of films being produced at the studios in 2008, due to ongoing negotiations in the US between studios and writers on revenues from downloaded films.