Williams: Heidfeld decision not an easy one.

BMW WilliamsF1 team boss Frank Williams has admitted that having to choose between test driver Antonio Pizzonia and late contender Nick Heidfeld was not as straightforward as recent testing results may have suggested.

As it had in 2000, when Jenson Button and Bruno Junqueira were the candidates to partner Ralf Schumacher, Williams had to select either Pizzonia or Heidfeld to link up with Mark Webber in the 2005 line-up. In the end - and it was right at the last minute - the team confirmed that Heidfeld had got the nod over his Brazilian rival.

"It wasn't an easy decision for us to make, as there was little to choose between the two of them," Williams revealed after Heidfeld had been confirmed at the team's launch in Valencia, "We were in the fortunate position to be able to choose between two drivers who would be a credit to any Formula One team but, ultimately, it is Nick who got our vote.

The announcement followed an extensive evaluation process that commenced in November last year, and saw Heidfeld and Pizzonia test for twelve full days each. The Brazilian, despite being disappointed by the decision, has apparently confirmed that he will stick with the team in the role of test and reserve driver in 2005.

"I am delighted that we have strength in depth, with Antonio taking up this position," Williams admitted.

Heidfeld was understood to be the choice of BMW Motorsport director Mario Theissen, who persuaded Williams to test the Jordan refugee at the end of the 2004, but Theissen was quick to praise the feedback provided by all three drivers during winter testing.

"All three drivers were very strong in the most recent tests - not only behind the wheel but also when working together with the engineers," he said, "The new team has grown together quickly and harmoniously. I'm very pleased for Nick, who earned the seat with his strong performance, and Antonio knows that, as a test driver, he is also taking on a key role in the team."