Australian cycling star Richie Porte will join BMC, confirming widespread speculation about the move.
Porte had said before last month's Tour de France started that he would probably leave Sky, where he has ridden since 2012, for next season.
"I was close to coming to BMC four years ago," Porte said in a team statement.
"This time, it was a hard decision, but the right decision."
The Tasmanian ace again played a crucial domestique role as his good friend Chris Froome won the Tour for a second time.
Porte also was a key lieutenant for Brad Wiggins when he won the Tour de France in 2012 and for Froome the following year.
He left Sky because he wants to pursue his own ambitions in Grand Tours such as the Tour de France.
Porte and American Tejay van Garderen will now be BMC's two main riders at the Grand Tours.
"I want to win races like Paris-Nice and Catalunya again and I think next year at the Tour de France, why not have Tejay van Garderen and me there? We get along well," he said.
"It is exciting to be going to a team where I am going to have so many opportunities for myself to win races."
Van Garderen was running third at this year's Tour, but dramatically pulled out in the last week.
After opening this season with nine wins, Porte led Sky's team at the Giro d'Italia, another three-week Grand Tour.
Porte made a promising start, but eventually pulled out after a string of mishaps.
Porte adds to the strong Australian contingent at BMC, which began with 2011 Tour de France winner Cadel Evans.
Rohan Dennis, who won stage one of this year's Tour, and Campbell Flakemore are currently on the BMC roster.
"Obviously, Cadel left his legacy with the team," Porte said.
"When he was racing, it was almost like it was partially an Australian team.
"There were always so many Aussies at the races with BMC caps on.
"With them still having Rohan and Campbell - who is from Tasmania like me - the team still does have a fairly Australian flavour."