Dec.3 (GMM) HRT's technical director Toni Cuquerella has acknowledged that the Spanish team's F1 foray is now over.
It was believed the team's departing owner Thesan Capital had set an end-of-November deadline for a new buyer to be found.
But subsequent reports in Spanish newspapers suggested the dream may not be over for the team, who may have been granted more time by the governing body to pay next year's entry fee.
However, leading team figure Cuquerella wrote on Twitter: "Four years ago, I suggested to a friend to make a F1 team.
"Today after three seasons the last page of HRT has been written.
"It was certainly an experience," the Spanish engineer concluded.
Ferrari test driver Marc Gene, another Spaniard, commented: "It leaves a bad taste, because the probability of another Spanish project (in F1) is small and the precedent is negative.
"Support in Spain normally goes to the drivers," he is quoted by the EFE news agency.
"I can think of several projects in which it was thought that the country would get behind it, but instead only the athletes are supported," added Gene, a former Minardi driver.