Just one seat remains vacant on the 2011 Formula One grid following Narrain Karthikeyan’s appointment at HRT F1.

The second HRT slot is still to be filled, with several drivers including 2010 HRT pilots Karun Chandhok, Christian Klien, Bruno Senna and Sakon Yamamoto reportedly working on finding the required budget to compete.

The new season will see no changes to the driver line-ups of the sport’s top five teams, with Red Bull, McLaren, Ferrari, Mercedes and Renault all electing to retain their 2010 drivers.

This year’s field will include at least four rookies, with 2010 GP2 drivers Pastor Maldonado, Sergio Perez and Jerome D’Ambrosio joining Williams, Sauber and Virgin respectively, in addition to 2010 DTM Champion Paul di Resta’s expected appointment at Force India.

The 2011 grid will be one of the most culturally diverse in years, with at least 13 nationalities being represented.

Germany again leads the way with five drivers, from Great Britain with three.

Perez’s signing means a Mexican will join the field for the first time since Hector Rebaque competed with Brabham in 1981, while Maldonado will become the first Venezuelan in Formula One since Johnny Cecotto competed with Theodore in 1984.

D’Ambrosio will also end a considerable driver-drought for Belgium, with the country not represented since Bertrand Gachot’s 1995 campaign for Pacific Grand Prix.

Of those who competed in the final race of 2010, Nico Hulkenberg, Tonio Liuzzi, Nick Heidfeld, Lucas di Grassi, Bruno Senna and Chistian Klien are all yet to secure a drive.

It is expected that Hulkenberg will take on the reserve driver role at Force India, while Tonio Liuzzi has a contract to race with Force India – a situation which the team is yet to resolve.

The 2011 Formula One World Championship kicks off in Bahrain on March 13.

See below for an unofficial entry list

Red Bull Racing Renault

1 Sebastian Vettel (DEU)

2 Mark Webber (AUS)

Vodafone McLaren Mercedes

3 Jenson Button (GBR)

4 Lewis Hamilton (GBR)

Scuderia Ferrari Marlboro
5 Fernando Alonso (ESP)

6 Felipe Massa (BRA)

Mercedes GP Petronas F1 Team

7 Michael Schumacher (DEU)

8 Nico Rosberg (DEU)

Lotus Renault GP

9 Robert Kubica (POL)

10 Vitaly Petrov
(RUS)

AT&T Williams (Cosworth)

11 Rubens Barrichello (BRA)

12 Pastor Maldonado (VEN)

Force India F1 Team (Mercedes)

14 Adrian Sutil (DEU)

15 Paul di Resta (GBR)

Sauber F1 Team (Ferrari)

16 Kamui Kobayashi (JPN)

17 Sergio Perez Mendoza (MEX)

Scuderia Toro Rosso (Ferrari)

18 Sebastien Buemi (SWI)

19 Jaime Alguersuari (ESP)

Team Lotus (Renault)

20 Jarno Trulli (ITA)

21 Heikki Kovalainen (FIN)

Hispania Racing F1 Team (Cosworth)

22 Narain Karthikeyan (IND)

23 TBA

Marussia Virgin Racing (Cosworth)

24 Timo Glock (DEU)

25 Jerome D’Ambrosio (BEL)