NEW YORK (CNN/Money) - The David and Lucille Packard Foundation board is set to hold its quarterly meeting Friday and possibly could kill Hewlett-Packard Co.'s $24 billion takeover of Compaq Computer.

The Los Altos, Calif.-based Packard Foundation, which holds nearly 10 percent of HP's stock, could cast the deciding vote on the merger. Three Packard family members sit on the 12-member board, which has yet to announce whether it will back the transaction or oppose it.

Chances of a decision are 50-50 and the foundation board could just as easily ask for more time to decide, people with knowledge of the situation said.

"If they have an announcement they will make it," a foundation spokeswoman said, declining further comment.

If the board does reach a decision, it likely will be made after 4 p.m. Pacific Time, another source said.

In September, Hewlett-Packard agreed to buy rival Compaq Corp. in a bid to bolster their competitive positions in a sagging market. However, the merger has faced increased opposition from both analysts and shareholders.

The managements of both Compaq (CPQ: up $0.14 to $10.00, Research, Estimates) and HP (HWP: down $0.05 to $17.85, Research, Estimates) remain committed to the merger. And talks between the companies and the foundation have continued. HP CEO Carly Fiorina and Compaq CEO Michael Capellas made a presentation to the foundation's board Wednesday, sources said.

"We've been having an open dialogue with the foundation board members and their advisors," an HP spokeswoman said.

Booz Allen Hamilton, the consulting firm hired by the foundation, is set to make a presentation Friday, people familiar with the situation said.

HP and Compaq have not set shareholder votes on the merger but some believe it could occur in February at the earliest.

Heirs of founders Walter Hewlett and David Packard already have come out against the deal. David Woodly Packard has indicated he will vote against the $20 billion purchase. The announcement followed an earlier decision by Walter Hewlett, along with his sisters Eleanor Hewlett Gimon and Mary Hewlett Jaffe, to vote against the HP/Compaq merger if it is presented to shareholders.

The heirs control about 7 percent and, combined with a negative decision by the Packard Foundation, could create an insurmountable block for the merger.

Walter Hewlett renewed his attack Wednesday, stating in a filing with the Securities and Exchange Commission that the market value of the combined companies has dropped by $6.2 billion since Aug. 31. Compaq's share price has fallen nearly 18 percent while HP's stock has shed more than 5 percent, Hewlett said.

Institutional Shareholder Services, the prestigious firm that advises institutional investors in proxy contests, is representing the shareholders of both Compaq and HP.

"ISS has not even reached a preliminary conclusion of the viability of this deal for either Compaq or HP shareholders," spokesman Pat McGurn said.

Influential Bear Stearns analyst Andy Neff, who predicted the HP/Compaq merger early this year, said opposition from ISS would significantly reduce the odds of the deal being approved.

But shareholders still will end up deciding the fate of the transaction.

"We still think that the deal will go to a vote regardless of the outcome of the Packard Foundation," Neff said.

Compaq declined comment.