Sutil says he has done all he can

Force India Formula One driver Adrian Sutil of Germany speaks to TV crew at the paddock of the Singapore F1 Grand Prix at the Marina Bay street circuit in Singapore September 22, 2011.

(Reuters) - Adrian Sutil said he had done all he could to secure a Formula One comeback with Force India on Thursday but felt the team's decision would be about more than just talent.

Stepping back into the cockpit for the first time in more than a year, the 30-year-old German completed 78 laps in testing at Barcelona's Circuit de Catalunya and clocked the eighth quickest time.

Force India are testing Frenchman Jules Bianchi, Sutil's rival for the last vacant seat on the grid, on Friday and the German hoped a decision would not be long in coming.

"I think it was obvious today that I could show I am still quick and that was very important," he told reporters.

"I don't know who has the better chance. I've done everything I can do to get my comeback and now it's up to them to decide."

The delay in naming a second driver, with Sutil a known quantity after racing for the team for five years up to the end of 2011 and Bianchi the reserve last season, has prompted speculation that the key factor will be commercial.

Sutil said that if it had merely been a question of securing the best driver, the situation would have been resolved before the first test in Jerez at the start of February.

"It can't take long anymore. In three weeks there is a race in Melbourne so it's about time to confirm the drivers," he added.

"There is some business behind it, I don't really know. For me the most important thing was to deliver a performance here. I have done my part...I can sleep without worries."

The season starts in Australia on March 17 but teams do not have to confirm their drivers until the week of the race.

"We're giving everyone the amount of mileage they need. We'll try and get all the information we've been collecting over to the shareholders this weekend and then it's their decision," deputy team principal Bob Fernley told Sky Sports television before Sutil began his test session.

"We want to make sure that it's an even playing field for everybody and that, more importantly, they have got the opportunity to get used to the car. Obviously one of them will come through and we don't want to disadvantage them in any way," he added.

Sutil, convicted of grievous bodily harm last year, was dropped by the team at the end of 2011 to make way for compatriot Nico Hulkenberg, who has now moved on to Sauber.

The test could be his last chance of a comeback after he was given a suspended 18-month jail sentence and fined 200,000 euros for a post-Chinese Grand Prix incident in a Shanghai nightclub in April 2011.

The incident left Eric Lux, then chief executive of Renault F1 (now Lotus) team owners Genii Capital, needing stitches for a neck wound caused by a champagne glass. (Reporting by Alan Baldwin in London; Editing by Clare Fallon and Alison Wildey)