Ecclestone held talks with Red Bull owner Dietrich Mateschitz with regard to the prospect of Hamilton joining forces with triple-world champion Sebastian Vettel and forming a super team.
The deal, however, foundered as the Austrian opted to remain loyal to Mark Webber.
Although Webber confirmed discussing with Ferrari the prospect of a move last season, the Australian ultimately decided to sign another one-year contract with Red Bull, so closing the door for Hamilton.
"Dietrich is a very honest, straightforward guy and told Mark the door was open for him to stay. That was good of him," said 82-year-old Ecclestone, speaking to the Mail on Sunday.
"Had Mark gone, Dietrich would have signed Lewis. Sebastian wouldn't have cared if Lewis had signed for the team."
Ecclestone also revealed Hamilton was initially dismissive of a switch to current team Mercedes.
The Briton eventually signed a three-year deal with the Brackley-based marque at the end of September, ending his 13-year association with McLaren.
Recalling the conversation he held with 28-year-old Hamilton at the time, Ecclestone initially suggested: "Why not talk to Mercedes, Lewis?"
As for Hamilton's response, Ecclestone claimed: "Lewis rolled his eyes, but I told him he had nothing to lose as he wanted out of McLaren."