Rio Haryanto's hopes of returning to the Formula One grid in 2017 have been dealt a major blow after losing sponsors Pertamina.
Haryanto drove for Manor in the first 12 races of 2016, only to lose his seat after the state-owned Indonesian energy company failed to secure the money required for the second half of the year. Haraynto stayed with Manor in a reserve driver role and has been linked with a return to the team since Esteban Ocon's departure to Force India.
However, he will need to find new backers to secure a drive after Pertamina confirmed it was ending its affiliation.
"This year there will not be a continuation of participation by Pertamina in F1," a Pertamina spokesperson told Reuters. "Of course we regret this very much, but we have already made maximal efforts for Rio and Indonesia."
Pertamina have been long-term backers of Haryanto and are believed to have put up around £4.23 million to secure him the Manor drive last year. Manor is yet to confirm either driver but is expected to wait until it has finalised talks with new investors.
Despite the loss of sponsorship, Haryanto's manager Piers Hunnisett is confident the Indonesian can secure a drive in the coming weeks.
"We are still working on a plan to keep Rio in Formula One," Hunnisett told Reuters. "People in the Formula One world felt he did a good job and he deserves to be there."
Other than Manor, the only other likely destination for Haryanto seems to be Sauber, though Hunnisett appeared to confirm speculation the team is nearing a deal with Mercedes junior Pascal Wehrlein.
"Obviously, we were hoping to move into a team like Sauber -- that was the plan but things are going to slow down a little bit."