Sauber has confirmed Tatiana Calderon as its test driver for the upcoming Formula 1 season.
The Colombian joined the team in 2017 as its development driver.
Calderon, 24, will combine her programme with her race duties in the GP3 series, where she will line up for Jenzer.
“I am very pleased to confirm my role as test driver for the Alfa Romeo Sauber F1 Team in the 2018 season,” she said.
“This collaboration will build upon the experience that I have gained as Development Driver with the team over the past year, and I look forward to continuing on this positive path together.
“I have been able to substantially expand and develop my skills as a race driver, and I am convinced that I will be doing so throughout this year.
“I would like to thank the Alfa Romeo Sauber F1 Team for this marvellous opportunity, which would not have been possible without the long-term support that I am receiving from Escuderia Telmex.
“I look forward to this season, and will give my all to demonstrate my capabilities in both GP3 and Formula 1.”
Team boss Frederic Vasseur added: "We are very pleased to continue our collaboration with Tatiana as our Test Driver.
"Tatiana is a very hard-working person, who has impressed the team with her focus and dedication. She has made good progress as a driver, developing both her mental and physical capacities continuously over the past few years.
"We look forward to having Tatiana on board for our first chapter as the Alfa Romeo Sauber F1 Team."