The agency has been awarded a brief to develop television and print advertising for the Corolla across Europe until the end of 2006, when the model reaches the end of its lifespan.
CHI was awarded the Corolla business without a pitch. Its commercials are already in production and are set to break in January 2006.
The move poses a further threat to Saatchi & Saatchi's grip on Toyota's centralised European business. Toyota is one of Saatchis' biggest global accounts after Procter & Gamble, spending more than $2.5 billion annually.
CHI first started to make inroads on the Toyota business last year, when it won the £8 million brief to launch the Aygo across Europe.
The agency created two ads, which were supported by a wider communications strategy including events and a track created by the DJ Paul Oakenfold. The work was rolled out across all 25 of Toyota's markets in Europe.
The work CHI creates for the Corolla will not automatically run in the UK. The business is expected to be handled in the same way as the Aygo account, where CHI creates an idea that is then offered as an option across Toyota's 25 markets across Europe.
According to Toyota's UK commercial director, Paul Philpott, Saatchis' work will continue to run in the UK.
"All commercials in the UK for Corolla will be Saatchi & Saatchi-produced until the end of next year," he said.
Last year, Saatchis relaunched the Corolla in the UK with a campaign aimed at 20- to 30-year-olds.
The first execution, called "stolen car", shows a surfer running out of the sea, pretending that he owns a passing Corolla. A second commercial featured a young man proudly test-driving one of the cars.
Toyota spends £11.5 million a year on advertising the Corolla in the UK, a figure that accounts for a quarter of Toyota's £43.5 million UK adspend, according to Nielsen Media Research.
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