
The project, which broadly aims to create an open platform for internet-connected TV devices, now counts ITV, BBC, Channel 4 and Five among its backers, plus the ISP Talk Talk and BT.
Now, the venture's six backers are seeking additional partners to come on board. The backers' said: "Any venture that wants to support the open internet-connected TV platform and can commit financial and marketing support to the project is invited to contact the partners."
For now, the venture is awaiting BBC Trust approval for the BBC's involvement - which is critical to its success. The BBC Trust is expected to deliver a final decision on the BBC's participation within months.
The partners plan to form a new joint venture to develop the technical specification for Internet-delivered TV and create and market a new consumer brand, build a common user interface, and build the technology platform.
The canvas partners have proposed that all prospective venture partners should be granted an equal proportion of shares in the new joint venture company.
Project canvas programme director Richard Halton said: "Internet-connectivity is going to have a transformational effect on TV.
"The potential for innovation goes far beyond bringing video-on-demand to the TV set and there's a huge opportunity for a wide range of new commercial models to thrive. We always wanted all the UK's public service broadcasters and at least two ISPs to be involved in the venture at launch, so we're delighted that Channel 4 and Talk Talk have joined the project.
"Today we're inviting any further expressions of interest from other companies to join the venture. We hope that any other businesses that share a similar vision for internet-connected TV will want to be a part of this story."