Current Williams driver lineup Valterri Bottas and Felipe Massa are to be retained for the 2015 season,  the Grove team have announced.

The former Constructors title winners are keen to hold on to their driver lineup which has delivered the team's most successful season for some years. Bottas in particular has impressed, delivering a string of podium finishes and strong Qualifying performances. Massa secured the team's first pole position since the 2012 Spanish Grand Prix in Austria earlier this year.

Williams currently sit 4th in the Constructors Championship, battling with Ferrari for third place. This comes after a 2013 season where Sir Frank Williams' team only picked up 5 points throughout the whole campaign.

Deputy Team Principal Claire Williams is pleased with both of their drivers. "I think they have both shown they can deliver what we need them to. Valtteri, everyone’s seen what a competitive season he’s had so far, four podiums in the last five races. Felipe, as we all know, has had some bad luck but he’s quick and we know he will deliver.

Their successful season is attributed to their Mercedes engine, which is the engine to have this season, with it leaving competitiors Ferrari and Renault far behind. Williams this season have had a car which is arguably the fastest in a straight line, with their cars excelling in the tracks which include long straights, e.g. Austria and Monza, with strong Qualifying results in both races.

Bottas is seen as one of the future World Champions, and there were rumours that McLaren we're looking to sign him for the 2015 season, but this news means the Woking based team will have to look elsewhere. Massa signed a three year contract this year when he signed from Ferrari, he will continue to show his experience and help the team, and also he can help Bottas develop.

In terms of the Driver's championship, Bottas sits in an impressive fifth with team mate Massa in ninth. The team will continue to grow and perhaps can get back to their glory days of the 80's and the 90's.

It remains to be seen whether test and reserve drivers Felipe Nasr and Susie Wolff will be retained, with Nasr currently in GP2 and Wolff being the team's development driver.