Formula One defending champion Lewis Hamilton is close to agreeing a new bumper contract with Mercedes

Lewis Hamilton's contract with Mercedes runs out at the end of the year. Credit: PA

Lewis Hamilton remains hopeful of signing his bumper new Mercedes contract before he opens the defence of his Formula One championship in Melbourne next weekend.

The new season gets under way a week on Sunday, and following a strong fortnight of winter testing, Hamilton will start as the firm favourite to claim a fifth world title.

The 33-year-old British driver is out of contract at the end of the year, but speaking in Turin on Wednesday, he anticipates dotting the i's and crossing the t's on his new deal in the very near future.

Hamilton's new contract, which is expected to take him through to the end of the 2020 season, is set to earn him up to £40million-a-year.

"I hope it will happen (before Melbourne)," Hamilton said. "We have of course got this year to focus on, but it will happen.

"We have been talking and continue to talk. It is quite a relaxed atmosphere for us because Mercedes know I am committed to them, and they have expressed they are committed to me.

"I sit here quite relaxed. It is about constantly trying to find common ground.

"Ultimately with contracts and partnerships you always want to work on how you can do better and to provide that service and vice-versa, by how you can extract more from each other so that is what we are working on."

Mercedes' executive director Toto Wolff, sporting a small hand cast here after breaking his thumb while skiing, was more succinct in his assessment of Hamilton's new deal.

"It's all good," he added with a smile.

After eight days of testing and number-crunching, the common perception is that Hamilton's Mercedes team will once more hold the edge over their rivals.

Hamilton will start the new F1 season as firm favourite to reclaim his title. Credit: PA

Although Ferrari's Sebastian Vettel set the fastest time of the winter at Barcelona's Circuit de Catalunya, Mercedes again showed off their bulletproof reliability, while also impressing in race-style simulations.

Much has been made of Hamilton's desire to continue in F1 and cast his name alongside the sport's immortals by becoming only the third driver - after Juan Manuel Fangio and Michael Schumacher - to win a fifth championship.

But the Englishman appeared full of vigour in Italy on Wednesday as he laid out both his and Mercedes' plans for further domination this term.

"We really have pushed the envelope so far in the past four years and that is why we have been the leaders," Hamilton added.

"I go to the factory every week and see what it is happening and there is no coincidence that we are world champions and we are number one.

"The great thing is that we are always wanting to move forward. If I saw anything within my team that wanted to compromise and wanted to stand still then I would know that I am in the wrong place, but I don't and I am not.

"It is a new beginning for us this year. It is not like we are four-time world champions. We want to win that championship again and there is one more to get."