Force India were sitting comfortably on sixth position four races ago but Sauber reduced the gap by securing 38 points in their last four races, even as the Indian team failed to finish within the top-10 bracket in the last two races.
Going into the Indian Grand Prix, Force India are just 17 points ahead of Sauber.
Mallya said they have invested a lot in preparing the car for 2014 season but at the same time they are hopeful of keeping fast-catching Sauber at bay in the remaining four races in this season.
"Hopefully we will hang on to our 6th position in the championship. Sauber is coming dangerously close to our team. We are heading in the right direction. Having said that the results will speak for themselves," Mallya said.
"Whatever we have suffered this year will be a good investment for the next year," he added.
