Force India is set to announce Sergio Perez for 2016 in the coming days, despite the Mexican and his sponsorship being linked to the Renault/Lotus deal.
The team has already confirmed Nico Hulkenberg for next season, but deputy team principal Bob Fernley says that the delay on Perez is simply because the deal he has to conclude with team boss Vijay Mallya is more complicated than that involving the German.
"Vijay is finishing off the discussions with him, and I think by Singapore we should be clear to announce everything," Fernley told Motorsport.com.
"One deal is more complex, there are commercial issues involved, whereas the other is a driver contract."
Fernley insists that driver continuity is good for the team, and says that Hulkenberg's decision to stay was an indication of his faith in the Silverstone outfit.
"We have two drivers that get on well within the team, they're pushing each other all the time. Both of them are excellent racers. I'm not sure that we could do better, that's the key.
"I think that they are both very happy at Force India.
"Obviously Nico had a choice, and he's made that choice, and I think it's the same thing probably with Checo. Nico was out of contract, Checo's is a renewal."