Bernhard Eisel has signed a three-year contract extension that will see him remain at Team Sky until 2015.
The Austrian said it was "one of the toughest decisions of [his] life" because of his close friendship with Mark Cavendish, who left the Tour de France-winning team earlier this week.
"The fact that Mark Cavendish is leaving us made this one of the toughest decisions of my life, and I wouldn't have stayed if I hadn't felt absolutely at home here," said the 31-year-old.
"Mark and I have ridden together since 2007 and he was my only room mate during most of that time. I haven't just looked after him on the bike, I also regard him as a brother, so it will be strange competing against him in the future."
Cavendish left the British team to join Omega Pharma-Quick Step, who will support the 'Manx Missile' in his bid for stage wins.
