Last year's European Formula 3 champion Ocon was brought into the Mercedes fold earlier this year, becoming official reserve driver for its DTM squad alongside his GP3 commitments with ART Grand Prix.

The Frenchman, who heads into this weekend's GP3 finale with a two-point lead in the standings, has been tipped for a DTM switch next year, with Pascal Wehrlein in the running for a Manor Formula 1 drive.

Ocon has already made several appearances in F1 machinery, most recently for Force India in June's Red Bull Ring test, but has yet to drive for Mercedes.

"We have taken up the option on him because he has been with us following the DTM team for a while now," said Mercedes motorsport boss Toto Wolff.

"[He is] test driver in DTM and has integrated well, and he's doing a very good job in GP3.

"He's somebody we would very much like to have in the family this is why we exercised the option."

Wolff added that Ocon's 2016 programme has not yet been finalised, and that no decision had yet been made about DTM champion Wehrlein's future.

"It doesn't mean we have found a solution for Pascal, because the current driver market is difficult," said Wolff. "Most of the teams have already announced drivers so it needs to be right deal.

"But having taken up Esteban, we are conscious we have to find a suitable programme for both of them – it could be for both of them a testing role, a Formula 1 role or a DTM role."