Nico Rosberg is backing former Mercedes teammate and title rival Lewis Hamilton to triumph in the fight for the 2018 Formula 1 world championship.

The German retired from F1 after sealing his maiden championship in 2016, having pipped Mercedes teammate Lewis Hamilton to the title by just five points in a tense season-finale in Abu Dhabi.

It marked the first time Rosberg had beaten Hamilton in the drivers' standings after four years together as teammates at Mercedes. The pair endured an rocky relationship as they went head-to-head for titles, with Hamilton coming out on top in 2014 and 2015, before Rosberg prevailed in 2016.

Hamilton recovered from his 2016 setback to secure his fourth world championship crown last season, as Mercedes fended off a significant challenge from a revitalised Ferrari squad spearheaded by Sebastian Vettel.

And Rosberg believes his once fierce rival will beat Vettel again in 2018, but by a much smaller margin.

"My prediction corresponds to what happened last year," Rosberg told German television station RTL. “So Lewis Hamilton wins, this time just one point ahead of Sebastian Vettel.

"After that is Lewis' team-mate Valtteri Bottas and the two Red Bulls of Max Verstappen and Daniel Ricciardo.”

However, former Toyota F1 driver Timo Glock disagrees with his fellow countryman.

The German reckons Ferrari will mount an even greater title challenge in 2018 compared to the one it managed last year.

“I think Ferrari had a very good base last year and they can build on that," Glock added. But pressure can change a lot, even if we see a very exciting fight to the end."