Brazilian Antonio Pizzonia will race for Williams in the last two Grands Prix of the season. The 25-year-old test driver has been deputising for Nick Heidfeld since the German pulled out of Monza after suffering a series of headaches.
"I am delighted to be racing for another two races," said Pizzonia.
"The two tracks in Japan and China are real drivers' circuits and I hope to be able to validate this vote of confidence from the team."
Williams boss Frank Williams added: "On the strength of his races for the team thus far this season, we know he will serve us well."
The Formula One championship travels to Suzuka on 9 October and Shanghai two weeks later.
Pizzonia has accumulated eight points in five outings for Williams during his career.