Transformers character Optimus Prime, is displayed as a full size cab from a tractor trailer truck at the start of the red carpet at the Los Angeles premiere of Transformers: Revenge of the Fallen June 22, 2009. REUTERS/Fred Prouser

Summer box office sales narrowly hit a new record in North America -- with a little help from an angry memo written by Transformers director Michael Bay.

The filmmaker in May accused Paramount Pictures executives of fumbling the marketing campaign for his June 24 release Transformers: Revenge of the Fallen.

Right now we are not an event. We are just a sequel, which is very different, he wrote in the missive that was leaked to the media.

Fortunately for both parties -- if not for the overwhelming majority of critics who eviscerated the big-bang spectacle -- Paramount's marketing plan kicked into high gear and the movie became the top draw at the summer box office in North America.

The movie grossed $399 million in the United States and Canada, well ahead of the No. 2 choice Warner Bros.' Harry Potter and the Half-Blood Prince with $294 million.

When overseas sales are included, the rankings are reversed. Harry Potter earned $905 million worldwide, and Transformers $828 million.

The two franchise pictures helped the summer moviegoing season reach another record -- barely.

North American ticket sales totaled $4.18 billion for all films from May 1 through September 2, according to tracking firm Rentrak Corp. This represents a 0.01 percent rise from the year-ago haul of $4.14 billion.

Even in a tight economy, consumers seeking a great entertainment value continued to flock to movie theaters to see blockbusters across action, comedy, drama and family-friendly genres, said Ron Giambra, Rentrak's executive vice-president of Theatrical Worldwide.

Summer is the most lucrative season for the studios, with ticket sales accounting for as much as 40 percent of annual theatrical income. With their target audience of young males in mind, they unleash costly popcorn pictures loaded with explosions and special effects.

The top five was rounded out by the Pixar cartoon Up ($290 million), the surprise Warner Bros. bawdy hit The Hangover ($270 million) and Paramount's Star Trek reboot ($257 million).

That's not to say other demographic groups were completely ignored. Counterprogramming efforts such as The Ugly Truth ($86 million) and the early Oscar bait Julie & Julia ($71 million and counting), both from Columbia Pictures, scored with female audiences. Sandra Bullock enjoyed the biggest movie of her career (before adjusting for inflation) with Disney's The Proposal ($160 million), the No. 9 movie of the summer.

At the other end of the scale, notable bombs included Paramount's Eddie Murphy comedy Imagine That -- a $55 million project that grossed $16 million.

Universal struck out with such disappointments as the costly Johnny Depp gangster drama Public Enemies, which grossed $97 million, Sacha Baron Cohen's Bruno ($60 million), and Will Ferrell's Land of the Lost and director Judd Apatow's Funny People with about $50 million each.

Universal, a General Electric Co unit, lags the six major studios in market share so far this year, according to tracking firm Box Office Mojo (

Time Warner Inc's Warner Bros, leading in No. 1 openings this year, rules the pack with 20.6 percent, followed by Viacom Inc's Paramount (18 percent), News Corp's 20th Century Fox (12.5 percent), Walt Disney Co (12.1 percent), Sony Corp's Columbia (11.9 percent) and Universal (9 percent).