Friday 3 February at 09:35 : Feb.3 (GMM) HRT, the Spanish team that until now had the final vacancy on the 2012 grid, has finally completed its race driver lineup by signing Narain Karthikeyan.

The Indian began last year's championship with the back-of-the-grid outfit before he was replaced by Red Bull protege Daniel Ricciardo.

But with Australian Ricciardo moving to Toro Rosso for 2012, 35-year-old Karthikeyan - who briefly returned for his home race in India late last season - has taken back his full-time seat.

The news is a blow to Vitantonio Liuzzi, who had acknowledged that a driver with higher-paying sponsors could oust him for 2012 despite his long-term contract.

Karthikeyan will be Pedro de la Rosa's teammate.

"It has taken a lot of hard work to make this happen but I am absolutely elated to feature on the 2012 grid with HRT F1 team," he said in a statement on Friday.

De la Rosa will begin HRT's pre-season preparations at Jerez next week, before Karthikeyan drives at the second test, at Barcelona.