BERLIN — Michael Schumacher called off his much-anticipated Formula One comeback because of lingering neck injuries from a motorcycle crash six months ago.

The seven-time world champion was to fill in for injured Ferrari driver Felipe Massa, and hoped to return at this month's European Grand Prix in Valencia, Spain. Ferrari announced Tuesday that test driver Luca Badoer will race in Massa's place.

Schumacher said on his Web site he informed top Ferrari officials on Monday evening that "unfortunately I'm not able to step in for Felipe."

The 40-year-old Schumacher retired at the end of the 2006 season. Since then, he has raced occasionally in a motorcycle series before being injured in a crash.

"The consequences of the injuries caused by the bike accident in February, fractures in the area of head and neck, unfortunately have turned out to be still too severe," Schumacher said. "That is why my neck cannot stand the extreme stresses caused by Formula One yet.

"I really tried everything to make that temporary comeback possible. However, much to my regret it didn't work out."

The neck pain arose after testing an old Ferrari at the Mugello circuit in Italy, said the German star, who won 91 races in 250 starts in a 15-year career.

"I am disappointed to the core. I am awfully sorry for the guys of Ferrari and for all the fans which crossed fingers for me," Schumacher said. "All I can do now is to keep my fingers crossed for the whole team for the coming races."

Ferrari president Luca di Montezemolo thanked Schumacher for his loyalty to the team in attempting an F1 comeback.

"No doubt his return would have been good for Formula One and I am sure it would have seen him fighting for wins again," Montezemolo said. "In the name of Ferrari and all the fans, I wish to thank him for the strong attachment he displayed for the team in these circumstances."

Schumacher's manager, Willi Weber, said the crash in February was "the most serious accident that Michael had in his motor sports career."

"Michael was totally fit, that would not have been a problem," he said. "But after the first test laps, there were no improvements in the area of the neck muscles."

German Chancellor Angela Merkel also voiced regret that Schumacher could not make his comeback, saying that it is "a shame for him." but she added in an interview with RTL television that "I find it right that he is not taking any unnecessary risks."

Badoer, a 38-year-old Italian, was first floated by Italian media after Massa's crash last month took him off the race circuit.

Badoer said on Ferrari's Web site he had mixed feelings about his chance to drive in a F1 race.

"Since I've been a child I always wanted to race for Ferrari and now I've got the possibility to make this desire come true," he said. "I'm really sorry for Michael, because I know how much he wanted to return. I'm saying that as his friend and his fan."

Montezemolo said Ferrari decided to give Badoer "the chance to race for the Scuderia after he has put in so many years of hard work as a test driver."

The 28-year-old Massa underwent surgery on multiple skull fractures after he was hit in the helmet by a loose part from another car and crashed into a protective tire barrier during qualifying for Ferrari at the Hungarian Grand Prix.