Given the choice between a hit West End play and a successful Hollywood blockbuster, most producers would doubtless plump for the latter. However, artistic director Nicholas Hytner has claimed that War Horse will prove more profitable for the National Theatre than it will for Steven Spielberg's studio.

Despite the film taking more from its opening weekend in the UK and Ireland alone than the National's annual profit on the stage version, Hytner told Sky News: "I'll stick my neck out and predict the play will be more profitable to us than the movie will be to DreamWorks."

Last weekend, the movie took £3.94m at the British box office, more than double its closest rival The Iron Lady (£1.49m); in the US it has so far taken $67.5m. The National, meanwhile, has earned just under £3m a year from the West End production.

However, the film reportedly cost more than $70m to make, dwarfing the National's original production costs. And the theatre's earnings will most likely increase with the Broadway production, and others set for Los Angeles and Melbourne later this year. Its combined profits since 2009 stand at £10m, and the West End production, currently booking until February 2013, has a further advance of £6.7m. The theatre also has a stake in the film, though it has never owned the screen rights for Michael Morpurgo's novel.

Hytner explained: "We bought the stage rights for a novel for which the screen rights had already been sold. We're not movie producers so we wouldn't look for the movie rights, but we do have a stake in the movie because Dreamworks gave us a good deal on material that is specific to the play."

The National made £70.6m overall last year, of which 48% came from box-office revenue, while War Horse took £13.9m in the West End.