The boyband, who recently announced their split after 14 years, maintained that their decision to part ways is not a publicity stunt as they were offered a bigger deal to remain a group.
Member Nicky Byrne told the Daily Star: "It's not a publicity stunt. There was more money on the table from Sony Records as part of a re-negotiation but it feels right to see what else is out there."
The four-piece confessed that their long-time manager Louis Walsh tried to persuade them not to split up and vowed to smooth over any problems.
Mark Feehily added: "Louis said to us, 'Whatever is wrong we'll fix it,' but there's nothing to fix. It's a natural thing to happen. We couldn't go on releasing albums until we died."
The band insisted that their split is for good and that they will not be reuniting in the future like fellow pop acts Take That and Steps.
Byrne continued: "Other bands who have breaks know they might come back. We're saying we're not."
The group claimed that new boybands The Wanted, JLS and One Direction will not last 14 years together as it is not "normal".
Kian Egan said: "I don't see any of them lasting as long as we have."
Feehily added: "Four or five years max for a boyband is normal. We lasted as we all get along. We're quite freakish like that."
Westlife's new single 'Lighthouse' will be available to download on November 13, while their Greatest Hits collection will follow on November 21.
> Westlife add nine extra dates to farewell arena tour
Watch the music video for Westlife's new single 'Lighthouse' below: