In July, previous Channel Five owner RTL said it didn't view the scheme as a priority after learning the channel would be required to stump up £16m in funding for the project.
However, new owner Richard Desmond, who paid £103.5m for the broadcaster, believes the project will "shape the future of broadcasting and open up new and exciting possibilities for viewers" and has agreed that the channel should return to the venture.
"We're delighted to renew Channel 5's commitment to supporting Project Canvas following a review of our digital strategy," said Desmond.
"This is important to the future of Channel 5 and having an open internet-connected TV platform fits closely with our plans to bring brilliant new content and interactive services to viewers."
Project Canvas director Richard Halton said he was "delighted" to have the channel back on board.
"This is great recognition of how important Canvas is to the future of television".
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