Four-time Tour de France winner Chris Froome has said Team Sky “plan to be together” beyond next year if possible after broadcaster Sky announced it would end its investment in the team at the end of 2019.

The broadcaster, which is the majority owner and title sponsor of the team, will bring its involvement to an end after a decade, with the announcement plunging the future of the team and its riders and staff into doubt.

Press Association Sport understands Sky’s decision came as a ‘shock’ to team principal Sir Dave Brailsford, who has now set a deadline of next year’s Tour de France to seek new backing to continue the team.

Riders were told the news during their training camp in Mallorca, and were all smiles on social media during Wednesday’s training ride, with Tour de France winner Geraint Thomas showing off his new bike on Instagram.

Froome, who like Thomas joined Team Sky for their first season in 2010, used Twitter to thank Sky for their backing to date and to express confidence in the future.

“We are not finished yet by any means,” he wrote.

“Everyone at Team Sky has big ambitions for 2019 and this news has made us more determined than ever to make them happen.

“I can’t predict the future but I can say this with absolute certainty, this is a really special team. We plan to be together in 2020 if at all possible and we will all be doing everything we can to help make that happen – in different colours with a new partner but the same values, focus and desire to win.”

Sky’s decision comes after a £30billion takeover by US cable giant Comcast, though Team Sky chairman Graham McWilliam said the decision came from Sky and not the new owners.

“Now is the right time,” he wrote on Twitter. “The start of a new chapter for @SkyCorporate is a natural moment. 12 months gives @TeamSky time to plan for the next phase.

“The decision was taken by Sky in the last few weeks. Comcast are aware and supportive of what we have decided to do, but this is our decision not theirs. Now looking forward to a great final season with @TeamSky.”

Team Sky have been among the most successful teams in the sport over their nine-year history to date, winning 322 races, including eight Grand Tours. They delivered the first ever British winner of the Tour de France in Sir Bradley Wiggins in 2012 and have gone on to win six of the last seven editions.

The team had appeared confident the Comcast takeover would have little impact on them, and in recent months handed new long-term contracts to Thomas and 21-year-old emerging talent Egan Bernal among others.

In an open letter to fans on Wednesday morning, the team said they would look for new partners for 2020 and beyond, with a deadline of July.

“This news has only just been announced; we can’t predict what will happen from 2020 and there are no guarantees,” the letter read.

“Whatever happens, we will make sure there is clarity one way or the other about the future of the Team before the Tour de France next July.”

Wholesale changes of sponsorship and backing are common in road cycling, and Sky’s 10-year association is a long one by comparison to most.

But the likelihood of the team finding backers with the same deep pockets of Sky, who have ploughed more than £150million into the team, seems slim given the struggle other successful teams like Quick-Step Floors and BMC Racing have faced when seeking new sponsors of their own.

Sky had also sponsored British Cycling but ended a partnership, which began in 2008, at the end of 2016.

Bradley Wiggins became the first Brit to win the Tour de France in 2012Bradley Wiggins became the first Brit to win the Tour de France in 2012 (PA)

Team Sky was launched in 2010 with Brailsford setting the goal of winning the Tour de France with a British rider within five years.

Sky quickly delivered with Wiggins’ 2012 success before Chris Froome took over, winning the first of his four Tour titles in 2013. Froome’s Giro d’Italia win earlier this year made him the first rider in more than 30 years to hold all three Grand Tour winners’ jerseys at the same time.

In the summer, Thomas became the third Team Sky rider – as well as the third Briton – to win the Tour de France.

However, the team have faced plenty of controversy along the way.

Froome was the subject of an anti-doping case after his La Vuelta win last year, though it was dropped by the UCI a week before the start of this year’s Tour.

Starting in 2016, the UK Anti-Doping Agency conducted a 14-month investigation into a ‘mystery package’ delivered to then-team doctor Richard Freeman on the final day of the Criterium du Dauphine – won by Wiggins – in 2011.

A Parliamentary committee which held hearings into the case found the team had crossed an ‘ethical line’ by using the powerful corticosteroid triamcinolone to prepare for major races. The substance is banned in competition but legal out of it.

Wiggins denied that any drug had been used without medical need and hit out at the process, saying it was “so sad that accusations can be made, where people can be accused of things they have never done which are then regarded as facts”.

Team Sky also have plenty of detractors within cycling for tactics which many believe stifle racing.

Their superior budget has allowed them to employ riders who would be leaders elsewhere in a support capacity and effectively shut down attacks in the biggest races, something which has proved unpopular with many, particularly at the Tour de France.

It is understood Sky’s decision is not related to the controversies, which have followed the team for more than two years, but instead follows a review of its wider partnerships.