Klien had a successful 2003

The testing, with a possible Formula One drive at stake, will take place in Valencia from 25-27 November.

But the team have stressed it should not be seen as a shoot-out between Klien, 20, and the 28-year-old Bell.

A Jaguar spokesman said: "Until we test them it is impossible at this stage to make any type of prediction."

The team have yet to announce a partner for Australian Mark Webber for next year.

They are also looking for a test and reserve driver under new rules allowing them to run three cars in Friday practice at Grand Prix weekends.

Justin Wilson, who competed in the last five races of the season for Jaguar as a replacement for Antonio Pizzonia, remains in contention for the race seat.

Justin Wilson is under pressure

The Briton is under contract to the end of the year but facing stiff competition from experienced drivers including Austrian Alexander Wurz and Germany's Nick Heidfeld.

Sidhu said that while Klien and Bell's testing would look at speed, adaptability to the team and signs of long-term potential, sponsorship was also a consideration.

Klien is backed by Austrian energy drink brand Red Bull, who have been reported as pushing him for the full race drive rather than a testing position.

The Austrian was runner-up in German Formula Three this year and won the German Formula Renault title in 2002.

Bell hopes to become the first US Formula One driver since Michael Andretti left McLaren a decade ago.