NEW YORK -- As the October 8 deadline approaches for money market funds to join the Treasury Department's guarantee program, almost all of the industry's players have joined -- except, that is, for three of the largest companies.

As of Monday morning, Fidelity Investments, Vanguard Group and T. Rowe Price Group (TROW) , had yet to sign up to the program. The firms are almost the only holdouts that have not declared their intention to join.

The program, announced on September 19 in the midst of the largest-ever run on money market funds, is intended to calm investors fears. It insures all money market holdings as of September 19 in the event any funds break the buck. See full story

When asked for comment, Fidelity spokesman Vin Loporchio, said, "Fidelity believes the program is an interesting idea and is closely examining the specific details of the plan outlined last week by the Treasury Department. We will complete our analysis and announce our decision on whether to participate by the Department's October 8 deadline."

"Vanguard is considering participation in the Treasury guarantee plan and will make a determination by the October 8 deadline," said John Woerth, spokesman. He added that Vanguard's board is meeting on Tuesday to "discuss the program and Vanguard's participation in it."

Steve Norwitz, spokesman at T. Rowe, said the firm is still reviewing the details of the program and will make a decision before the deadline.

"Given the high quality ethos of the Vanguard Fixed Income Group I think it is extremely unlikely that they would ever find themselves in need of bailing out one of their money funds," said Dan Wiener, editor of The Independent Adviser for Vanguard Investors newsletter. Wiener speculated that if such a bailout were necessary, Vanguard could slap higher fees on its money market families to raise the cash.

Crane Data estimated that as of October 5, 70% of the $?3.?4 trillion in money fund assets were covered by the program. Some funds that have signed up have chosen not to insure their Government or Treasury funds, and that figure doesn't include Fidelity and Vanguard, which between them account for more than $600 billion of money fund assets. T. Rowe has about $16 billion in money market fund assets.

Treasury made the move to back up money market funds during the week of September 15, when two funds from The Reserve broke the buck -- fell below $1 a share net asset value -- causing panic among investors. See full story

While the industry has now bought into the Treasury program, at a cost of either 0.01% or .015%, questions still remain. It's also unknown whether the plan's costs will be pushed on to investors.

"I think the shareholders will pay for some if not all of it," said Connie Bugbee, managing editor of iMoneyNet. Average fees for what Bugbee said were "competitive" institutional accounts -- which typically include brokerage accounts -- are about 0.2%. In other words, some fund holders could see their fees increase by as much as 5% for the length of the plan.

Treasury has said the plan will be in place for three months, but may last a year. The decision to extend will rest with the Treasury Secretary Henry Paulson.

Bugbee questioned whether the plan needs to last longer, pointing out that most funds' holdings should have rolled over by then, and that investors that are going to pull out in response to September's panic would have done so by then. She added that she would be "very surprised" if, in the long run, a permanent insurance plan for the industry was introduced.

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