Force India unveiled their new car for the forthcoming Formula One season at Silverstone on Friday, but they are still to confirm the identity of British driver Paul di Resta's teammate.
The vacancy next to Di Resta is one of only three across the grid for the 2013 season, which begins with the Australian Grand Prix in Melbourne on March 17.
French driver Jules Bianchi, the team's third driver in 2012, was expected to be announced as Di Resta's teammate.
Former driver Adrian Sutil and ex-Sauber man Kamui Kobayashi have also been linked with the role.
Ferrari launch car
Milan: Fernando Alonso said Friday the battle for Formula One supremacy could be a lot tighter this year ahead of his bid to improve on two runner-up places behind Sebastian Vettel with a maiden title for Ferrari.
Last season's world championship was remarkable for the fact there were seven race-winners in the first seven races before Alonso went toe-to-toe with Red Bull ace Vettel in a decisive, thrilling finale at Interlagos.