As is always the case with the American-registered team, the length of the new contract was not disclosed, but a statement simply said the Australian will remain at the team "beyond the 2017 season".
Porte joined BMC from Team Sky in 2016 and has established himself as the team's clear stage race leader, building a core unit around him and putting together a string of results that have made him a big favourite for the Tour behind Chris Froome.
"We are on the eve of the biggest race of the year, and my biggest goal of the season, and I feel at home with my teammates and the management and staff. I have raced with a few teams throughout the years and I definitely think BMC Racing Team is the right fit at this point in my career as I try to win the Tour de France. I like the atmosphere and the way BMC Racing Team operates, so I am sure this is where I want to be.
There had been doubts over the future of the team, with general manager Jim Ochowicz confirming to Cyclingnews earlier this month that long-term backer Andy Rihs, the owner of BMC bicycles, was suffering health problems. The overwhelming majority of the team's riders are out of contract at the end of this year, but the re-signing of Porte is a sign that the team will continue into 2018 and perhaps beyond.
"Since joining BMC Racing Team last year, Richie Porte has developed into our outright General Classification leader. Richie's skill set and results speak for themselves and are in line with the team's goals and objectives throughout the season. In just over a year, Richie has become an integral part of this organization and it a pleasure to extend his contract," said Ochowicz in Dusseldorf on Thursday.