Sakon YamamotoColin Kolles has confirmed that Sakon Yamamoto is to remain at HRT for the foreseeable future.

Yamamoto was originally drafted in as a one-off at the British Grand Prix as replacement for Bruno Senna, but since then he has filled in for Karun Chandhok in the other seat. After suggestions in Belgium that Yamamoto will now see out the season, team principal Kolles has said that he sees no reason to replace the Japanese.

"I think that both drivers are doing a good job," explained Kolles. "We had the best qualifying result in Spa so far and Sakon's lap times were at the same level as Kovalainen's and Glock's in the race. I think there is no reason to make any changes so far."

Kolles said he was encouraged by the sponsor interest his team was gaining, and he is upbeat about its future.

"With more sponsors on board the situation is improving," he said. "As I mentioned before, in F1 you need a lot of support and this is what we are trying to achieve. Obviously this is a positive sign but we have to work hard to get as much sponsorship as possible for 2011."