The UK's new 12A certificate came into full effect this week as UIP released The Bourne Identity and Columbia TriStar re-released Spider-Man.

The Bourne Identity, the first film released in the UK with the new certificate, which allows audience members under the age of 12 access to the film if accompanied by an adult, opened with a strong gross of $3.35m (£2.15m), including $266,867 of previews from 338 sites on Thursday Sept 5. Playing at 419 venues the action thriller, which stars Matt Damon and Franka Potente, claimed an impressive $8,007 average per site.

However it could be argued that the figure was slightly disappointing given the potentially broader audience. 20th Century Fox opened Baz Luhrmann's Moulin Rouge with the old 12 certificate (meaning no under-12s were permitted) at 135 fewer sites over the same weekend last year to gross a superior $3.75m (£2.4m) - including $319,576 of previews.

With a new television and poster advertising campaign declaring 'Now you can take the kids for the ultimate spin' Columbia re-released Spider-Man to 305 sites and re-entered the chart in ninth place. The film's $424,627 (£272,186) brought its cumulative gross to $43.6m.

Only two other new releases managed to take top 15 places this week. BVI's The Importance Of Being Earnest, featuring an ensemble cast including Colin Firth, Reese Witherspoon, Rupert Everett and Judi Dench, took fourth place with $863,643 (£553,595). Playing at 215 sites it scored a good $4,017 average.

At 15 in the chart was Shane Meadows' Once Upon A Time In The Midlands from FilmFour. The $202,332 (£129,695) three-day take from 74 sites provided an reasonable, but ultimately disappointing $2,734 average. Sovereign's Indian-title Dil Hai Tumhaara ($144,145 at 23 sites) and UIP's Frailty ($133,253 at 100) were unable to make the chart.

Rounding out the top five, BVI's Insomnia played well in its second week dropping off just 28% to take second place with $1.3m (£839,499) from 265 sites and bring its 10-day total to $4.25m (£2.7m). In third UIP's comedy The Guru grossed a further $1.02m (£655,188) at 367 sites; while Columbia's Men In Black II landed fifth with $737,849 (£472,961), bringing its total gross to $33.1m.