Toyota Motor Corp president Akio Toyoda believes he has betrayed the team's fans after making the painful decision to axe the Formula One operation.

Toyoda, the grandson of the company's founder, insists he had to act for financial reasons, notably after Toyota announced the biggest loss in its history in March.

The world's largest car maker is now the third major manufacturer to withdraw from F1 in the space of 11 months after Honda and BMW.

Toyota's departure continues the exodus of Japanese companies from motor sport as Subaru and Suzuki withdrew from the World Rally Championship prior to this season.

In motorbikes, Kawasaki pulled out of MotoGP, whilst on Monday, tyre manufacturer Bridgestone announced they will not be renewing their supply contract in F1 after next season.

"Toyota Racing took part in 140 races and surely developed their ability one race after another," said Toyoda in a media conference in Tokyo.

"I would like to show my respect to their hard work in the competitions against top teams in the world.

"I would like to express my gratitude from my heart for sharing the dreams with them.

"I myself support motor sports, and have worked hard to make motor sports a part of motor culture.

"However, after taking the presidency in June, my situation has changed and I hope you can understand that.

"Since the economic crisis last year, we have discussed within our company whether we should continue in F1 or not, and our F1 team worked on the cost cutting. We have worked on all kinds of things.

"After the final race finished (Sunday's Abu Dhabi Grand Prix), we held an extraordinary board meeting and came to the conclusion we had to decide to withdraw.

"Betraying the fans was a hard thing to do, and I was the one who made the final decision."

Speculation surrounding Toyota's future was rife throughout the year, in particular after the parent company's financial results were aired.

However, Toyota soldiered on and signed a new Concorde Agreement with motor sport's governing body, the FIA, over the summer tieing them to F1 through to 2012.

It appeared at that stage any doubts as to their future had been erased.

But it is clear Toyota find the penalties they are likely to incur, and the cost of redundancies for the 650 staff at their Cologne factory a less painful financial pill to swallow.

Toyota will retain a presence in other forms of motorsport, but as Toyoda confirmed: "It's a complete withdrawal from F1.

"When I said a year ago we would continue, I had a serious intention to pursue that.

"However, after making efforts over the last year, we've reached this decision.

"As to other international races, we will continue with those we are taking part in at the moment."

Toyota's departure does at least open the door for Sauber to take up the now vacant 13th position on the grid.

After BMW confirmed their own withdrawal from the sport at the end of July, with their final race in Abu Dhabi, it left Sauber fighting for survival.

They were eventually taken over by Qadbak Investments Ltd in mid-September, just hours after Lotus were awarded the 13th slot.

The FIA agreed to the possibility of 14 teams competing in F1 next season on the proviso of there being unanimous agreement from all the other marques, which was not forthcoming.

It left Sauber playing an anxious waiting game these past few weeks, one that is finally over in the wake of Toyota's exit.

Following a strong start to the season, Toyota went on to finish fifth in this year's constructors' championship.

However, since their arrival in F1 in 2002 they failed to win a grand prix in 140 attempts, with the team's best result the back-to-back second places by Jarno Trulli in Malaysia and Bahrain in 2005.

It leaves drivers Trulli, Timo Glock and Kamui Kobayashi in limbo, although it was expected neither the veteran Italian nor the German would be re-signed.

Toyota's decision is particularly hard on Kobayashi who had driven superbly in the final two races in the absence of the injured Glock.

That led to Toyota Motorsport boss John Howett confirming in Abu Dhabi on Sunday the Japanese was "70 to 80% certain" of being given a contract for next year.

Just three manufacturers now remain in F1 - Ferrari, Mercedes-Benz and Renault - with the focus likely to switch to the latter in light of their previously precarious circumstances.