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.
"I have really enjoyed my first two years with BMC Racing Team so it was a natural decision to extend my contract," said Porte.
"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.
"I've had a great first half of the season and I think my results are a reflection of the way the team has created a really good training and racing environment for me. Things like having training camps at home in Monaco and building a core group of teammates around me from the first race of the year in Australia have really helped me. Whatever happens over the next three weeks, I'm looking forward to keeping the BMC Racing Team jersey on my back beyond the end of the season."
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.
"In 2017 alone, Richie has delivered the overall win at the Santos Tour Down Under and Tour de Romandie, second place at the Critérium du Dauphiné and four stage wins, so I think any team would be thrilled to have a rider of Richie's calibre in their ranks. We have the most important race of the year ahead of us and we felt it was the right moment to re-sign Richie so that his full concentration can be on the Tour de France. We already have full confidence in Richie and I think we are further demonstrating that with this announcement. We are excited to see what Richie does at the Tour de France and beyond with BMC Racing Team."