* Case threatens to break Briton's grip on motor sport
* F1 boss says German banker coerced him into payment
* Hearings expected to last until September (Adds fresh quotes, case adjourned until next week)
By Keith Weir and Jörn Poltz
MUNICH, Germany, April 24 (Reuters) - Formula One boss Bernie Ecclestone denied bribery charges on Thursday at the start of a trial in Germany that threatens to break his decades-long dominance of motor racing.
Prosecutors accuse the 83-year-old Briton of bribing banker Gerhard Gribkowsky by channelling $44 million to him in return for smoothing the sale of a stake in Formula One to private equity firm CVC eight years ago.
They say that Ecclestone favoured CVC as the new owner because it was committed to keeping him on as chief executive of the business.
The former used-car salesman, who became a billionaire by building motor racing into a global money spinner over the past four decades, is fighting to save his job and his reputation. He faces up to 10 years in jail if convicted.
"Gribkowsky did not tell the truth at crucial points," Ecclestone told the court in a 100-page statement read out in German on his behalf by his lawyer Sven Thomas.
Ecclestone maintains that he was the victim of coercion by Gribkowsky. He said Gribkowsky was threatening to make damaging claims about his tax affairs that could have cost him and his family much of their fortune.
"I saw my life's work in danger," he said in his statement, explaining that was why he had paid $22.7 million to Gribkowsky.
Ecclestone, wearing a dark suit, sat at a wooden desk flanked by his lawyers and with an interpreter at his side to translate for him on the first day of a case due to last until September.
CVC remains the largest shareholder in the business, which generates annual revenues of over $1.5 billion from its series of grand prix races around the world. CVC co-chairman Donald Mackenzie has said he would fire Ecclestone if he was found guilty of wrongdoing.
Despite his age, Ecclestone attends almost every grand prix race and remains central to the sport's commercial success. He has always dismissed talk of retirement, and there is no obvious replacement when he does finally quit or is forced out.
Uncertainty over his future makes it hard to revisit stalled efforts to launch a stockmarket flotation of Formula One, after a planned listing in Singapore was abandoned because of turbulent markets two years ago.
CVC paid about $830 million for a 47-percent Formula One stake that BayernLB had held from 2002-6 when banks took control of the business following the collapse of the Kirch media empire.
Gribkowsky, who is expected to give evidence in this trial, was jailed for more than eight years in Munich in 2012 for tax evasion and corruption in relation to payments from Ecclestone.
Peter Noll, who presided over that trial, is also the head judge in this latest case. Hearings will be held only once or twice a week to fit around Ecclestone's schedule, with the next one due on May 2.
The Ecclestone statement went back to his childhood during World War Two and recalled German bomber raids on the town of Dartford, close to London, before taking the court through his business career and the CVC deal.
It portrayed Gribkowsky, former chief risk officer at BayernLB, as a man who was after money and wanted to leave banking and get a role in the glamorous world of Formula One.
"We will see," was Ecclestone's phrase to try to rein in those ambitions.
The Formula One boss arrived at court in optimistic mood, telling jostling camera crews: "I'm confident, the sun is shining."
Ecclestone, who married for a third time in 2012 to a Brazilian woman more than 40 years his junior, defused some of the early tension in court when asked to clarify confusion over his marital status.
When asked if he was married or divorced, he at first replied "both." "I like to remember the divorce part," he said in English. (Editing by Mark Trevelyan)