Mercedes have announced the return of Valtteri Bottas as their third driver for the 2025 season.

The 35-year-old was available after leaving Sauber at the end of the 2024 campaign and will provide back-up to George Russell and Andrea Kimi Antonelli.

Bottas previously rode for Mercedes between 2017-21, winning 10 races and taking 20 pole positions.

He said: "I couldn't be more pleased. Despite the challenges of the past few years, I know that I've still got so much more to contribute to F1.

"Since I was a five-year-old kid growing up in Nastola, Finland, my focus has been on achieving success in the top tier of motorsport. I've been fortunate to have enjoyed many incredible moments in my 12 years of racing in F1 so far.

"I'm looking forward to using all the knowledge I've gained to help the team to perform and progress towards our goal of fighting for world championships."

Mercedes team principal Toto Wolff confirmed Bottas' experience and mentoring skills were crucial in the decision to bring him back.

Wolff said: "It's great to have [Bottas] back. His impact and contribution in the five years he was with us previously as our race driver was immense.

"Along with scoring multiple grand prix wins, he played a vital role in five of our championship victories.

"His technical feedback and input were important in helping us to those successes and pushing the team forward.

"In his role as reserve driver, all those qualities will be incredibly important in helping us compete for world championships and supporting both George and Kimi on track."