By Alan Baldwin
LONDON (Reuters) - Polish driver Robert Kubica completed a one-day test with Williams at Silverstone on Wednesday as he pushes for a Formula One comeback after a seven-year absence.
The former champions said it had been a "successful day" with the 32-year-old driving a 2014-specification FW36 car at the British Grand Prix circuit.
No lap times or any further information about the programme were provided.
The Pole, who won in Canada with BMW Sauber in 2008, is scheduled for a fuller assessment at Budapest's Hungaroring this month with Williams' British reserve driver Paul di Resta also due to feature in that two-day test.
Both are in the frame to replace 36-year-old Felipe Massa, should Williams decide not to renew the Brazilian's contract.
Kubica partially severed his right forearm in an horrific 2011 crash during a rally he entered for fun before the start of that Formula One season, and there are lingering doubts about his arm movement.
However, he completed 142 laps of the Hungarian Grand Prix circuit in August in a test with Renault (PA:RENA) that revealed no "obvious roadblocks", according to the French team.
He is being assisted by Germany's 2016 world champion Nico Rosberg, a friend and former rival who started his F1 career with Williams in 2006 before moving to Mercedes.
"He showed in the Renault test he is ready and there's no doubt about that anymore. Physically he is 100 percent in the car, so it's a really exciting time," Rosberg told Sky Sports television at the weekend in Japan.
"He did double race stints with Renault and was always on the pace so there's not that to prove. I think it's more about getting to know each other and see if it's a good fit."
Renault ended up taking Carlos Sainz on loan from Toro Rosso for next season as a replacement for Britain's Jolyon Palmer, with the Spaniard joining the team already for next week's U.S. Grand Prix in Austin, Texas.
Toro Rosso are switching from Renault to Honda engines next season, with Sainz joining the French manufacturer as part of the deal.
"I think he (Kubica) got really unlucky with Renault. In that moment suddenly Sainz became free because of the whole engine mix, but that's how it works," said Rosberg.