Members and associates of the Packard family have voted to oppose the merger between HP and Compaq - a decision that could sink the $25 billion deal.

Board members of the David and Lucile Packard Foundation, voted against the deal. The foundation owns 10.4 per cent of HP - sufficient to swing the shareholder vote on the merger when that vote occurs, probably in February.

In a joint statement, HP and Compaq said they would move forward with the merger plan, despite the lack of support from the Foundation and other family members.

"We're disappointed by the Packard Foundation's preliminary decision," the companies said. "Nevertheless, our responsibility to shareowners, customers and employees requires that we maintain a pragmatic view of the business and a focus on the future."

Family members of co-founder William Hewlett also oppose the deal. Walter Hewlett recently filed papers with the US Securities and Exchange Commission highlighting the poor financial performance of the two companies since the merger was first announced.