Lewis Hamilton Mercedes deal could be worth £27m a year

Hamilton leads the 2015 championship with 43 points from the opening two races

World champion Lewis Hamilton expects to sign a new Mercedes contract this week that could be worth more than £27m a year.

The 30-year-old Briton, who has been handling negotiations with team bosses himself, says talks are complete and the deal is being finalised by lawyers.

Hamilton said: "It should be done this week. There is no reason it shouldn't.

"Honestly, it's 99.6% done. There's no negotiating left, it's just legal stuff."

BBC Sport has learned Hamilton, who joined Mercedes in 2013 after six years with McLaren, will earn about the same as he did under his first contract with the German team - a basic salary, paid in US dollars, of $31m (£20.9m) plus extensive bonuses.

Depending on how many races he wins, and whether he becomes world champion, these bonuses could easily take his annual earnings well over $40m (£27m).

The overall value of Hamilton's deal is fundamentally similar to F1's two other big earners and multiple champions, McLaren's Fernando Alonso and Ferrari's Sebastian Vettel.

Alonso is being paid $40m a year by McLaren and Honda for the duration of the three-year deal he has signed, which runs until 2017.

Vettel will earn a one-off $50m (£33.7m) in his first season with Ferrari in 2015 but less after that, according to senior sources.

The figure for this season is high because the German secured a deal that, for one year only, he would have all possible bonuses he could earn guaranteed, as a kind of golden handshake for joining the team.

After 2015, Vettel will revert to a basic salary of about $30m (£20.4m), with bonuses defined for wins and championship titles, according to sources close to Ferrari.

Hamilton, who leads the championship by three points from Vettel after two races this season, said the German's win for Ferrari in Malaysia on Sunday was a reminder that Mercedes would not have things their own way this year.

"It has given us a pinch to suggest, 'Oh, OK, we've got a race on our hands,'" he said.

"We're a racing team, and we will be quicker in the next race. We'll manage; we'll be absolutely fine.

Alonso missed the first race of the season in Melbourne after a crash in pre-season testing

"Ferrari are too close to us in the championship, so we'll work very hard to analyse what we learned and apply it so it doesn't happen again at the next race."

Hamilton said that after Vettel's victory, his thoughts turned to Alonso, who left Ferrari at the end of last season after losing faith that they could provide him with a competitive car. Last season was Ferrari's least successful for 21 years.

Vettel was only able to join Ferrari for this season because Alonso left after five years with the team, negotiating an early exit from a contract that was intended to run until 2016.

McLaren are struggling this season, qualifying at the back largely because of the lack of competitiveness of the brand new Honda engine.

Hamilton said: "I was sitting next to Sebastian and I thought to myself: 'What is Fernando thinking?'

"I remember when I left McLaren and joined Mercedes, we were better the next year. I had a good feeling then.

"But he's almost done the opposite of what I did. It could have been him (winning in Malaysia). It's just strange how things turn out."