* Hamilton signs two-year extension to end of 2020
* Four-times world champion still hungry for success
* Announcement likely to seal other driver decisions
* Bottas's confident of staying also
(Adds fresh Hamilton quotes, Vettel reaction)
By Alan Baldwin
HOCKENHEIM, Germany, July 19 (Reuters) - Four-times Formula One world champion Lewis Hamilton ended months of speculation about his future on Thursday by signing a new deal keeping him at Mercedes until the end of 2020.
No financial details were given but British media reports suggested the deal could be worth up to 40 million pounds ($52 million) a year and was likely to make Hamilton the sport's top earner.
The 33-year-old Briton would have been out of contract at the end of the season and the protracted negotiations have been an ongoing saga.
Hamilton also revealed to reporters at the German Grand Prix that another, unnamed, team had made an approach to which he 'didn't give any air'.
"You can make whatever assumption you want," he added, when asked whether it was Ferrari (NYSE:RACE).
The deal, finally signed this week according to team boss Toto Wolff in a statement, means the top three teams now have a leading driver under contract for the next two years.
There was no mention of Hamilton's current team mate Valtteri Bottas, whose place has yet to be confirmed, but the Finn told reporters separately that talks were moving forward and he expected some good news soon. started with the discussions at the beginning of the year, and then a few months later, and for a couple of days. Then I put it off as it was too stressful," said Hamilton, who conducted his own negotiations.
"I just kept delaying it. I had a contract in place so I didn't feel like I had to rush."
Hamilton has been part of the Mercedes "family" since he was in karting and secured backing from the German manufacturer and McLaren.
"I have never been happier inside a team than I am right now," he said. "I'm very confident that Mercedes is the right place to be over the coming years."
LINGERING DOUBTS
Mercedes have won both the drivers' and constructors' titles for the past four years but, despite having the hottest seats in the sport, there had been lingering doubts about Hamilton's intentions.
Former team mate Nico Rosberg stunned the team in 2016 when he won the title and then announced his retirement only days later.
Hamilton, who won his first title with McLaren in 2008, enjoys a celebrity lifestyle with plenty of interests -- mainly in music and fashion -- outside of Formula One.
He acknowledged as much when asked whether the new contract would be his last.
"Maybe in two years my life will be completely different and I will want completely different things to what I want now so I couldn't tell you," said the man who has won 65 grands prix and taken a record 76 career pole positions from 218 races.
"I still feel pretty great. I wasn't expecting to feel as excited as I am now in this signing to extend."
Hamilton is eight points adrift of Ferrari's Sebastian Vettel, also a four-times world champion, at the halfway point in the season.
The German greeted the news that Hamilton would remain a rival for two more years with some indifference.
"Well, congrats. I don't know why it took so long," he said. "I think it was pretty clear.
"I have my place and my mission and what I want to achieve and in all honesty, that's all that matters."
($1 = 0.7691 pounds)