"I want to thank (team boss) Cyril (Abiteboul), Tony Fernandes, (sponsor) McGregor and everyone who has worked so hard to make this happen," said van der Garde.
As for Force India, it appears Adrian Sutil is still a candidate, but on Friday the higher bets were being placed on the Ferrari-linked Frenchman Jules Bianchi.
The Silverstone based team denied the decision is all about money.
"The decision we will make will be for the benefit of the team," deputy boss Bob Fernley insisted, according to Reuters.
"And it doesn't necessarily follow that that is a financial requirement. In fact it's highly unlikely that it will be."
There might, however, be an engine link, with rumours Bianchi's drive could be crucially linked with a Ferrari engine deal for 2014.
"It's part of the decision-making process," Fernley said.
"It would be too simplistic just to say it is linked to an engine, because it's not the case at all."