Three more summer blockbusters - Transformers, Die Hard 4.0 and Ratatouille - make their international debuts this weekend, ramping up competition in a global marketplace already dominated by four major Hollywood earners.

Fox International's Die Hard 4.0, with Bruce Willis returning after more than a decade for a fourth installment of the action franchise, opens in 36 international markets, most of them smaller European territories, on the same weekend as its launch in North America (where it is titled Live Free Or Die Hard).

The sequel gets an 860-print opening in Germany and a 578-print launch in Russia on Thursday (June 28). On Saturday (June 30) it opens with 700 prints in Japan.

Fox will be hoping that in spite of the 12 year gap international audiences show the same enthusiasm for the new film as they did for earlier installments: the franchise's previous outing, 1995's Die Hard With A Vengeance, grossed $261.2m internationally, compared to $100m in North America.

The global potential of DreamWorks and Paramount's Transformers has led Paramount Pictures International (PPI) to open the film in several major international territories before its domestic launch next Tuesday (at the start of the extended July 4 holiday weekend).

Director Michael Bay's screen take on the Transformers robot toy line opens on Thursday with 510 prints in Korea, 603 prints in Italy and 350 prints in Australia. The sci-fi action epic arrives on the same day in Indonesia, Malaysia, New Zealand, the Philippines, Singapore, Taiwan and Thailand.

After screening last week at the Taormina Film Festival, Transformers could turn out to be another big international performer for Bay. Though the director's last film, The Island, flopped badly in the US, it still managed $127m internationally. And his 1998 smash Armageddon topped its impressive $201.6m domestic gross with a huge $352.1m international take.

Disney/Pixar's animated Ratatouille opens in Russia and Chile on Thursday, the day before the film's North American release, and in Columbia on Friday.

Buena Vista International (BVI) probably has good reason to hope that the Paris setting of director Brad Bird's tale of a rat chef and his human friend will boost the film's international performance. Pixar's previous offering, last summer's Cars, took $217.9m internationally, compared to $244m domestically; but Bird's previous project for the company, autumn 2004's The Incredibles, hit $370m internationally after gleaning $261.4m in North America.

BVI also opened Disney's Chinese co-production The Secret of the Magic Gourd in China on Wednesday.

Last weekend's international leader, PPI's Shrek The Third, will certainly feel the effect of the new entries, but its weekend total will be considerably boosted by openings in two big markets.

The animated DreamWorks sequel - which had grossed $189.2m internationally as of Wednesday - arrives in the UK on Friday with 1,100 prints and in Japan on Saturday with 550 prints. It also opens in Switzerland on Wednesday (June 27), Hong Kong and Israel on Thursday, and Poland, East Africa and South Africa on Friday.

Last weekend's second biggest international earner, Fox International's Fantastic Four: Rise Of The Silver Surfer, expands into Latin America this weekend. It gets a 149-print launch in Argentina on Thursday and a 574-print opening in Brazil on Friday. The comic book sequel's international total so far is $65.5m.

Another of last weekend's big four, Ocean's Thirteen, from Warner Brothers Pictures International (WBPI), has just one major-territory opening this weekend, arriving on 600 screens in Mexico on Friday. As of Thursday, the international take (including territories handled by both WBPI and partner Roadshow) for the crime caper sequel had reached $109m.