Investors who once saw the MotherRock energy-trading hedge fund as their meal ticket will be lucky to get a bowl of stone soup out of the deal.

The two-year-old fund, which once handled $450 million worth of assets but imploded last month after a disastrous summer, is telling investors not to expect to get any money back.

Mother Rock, led by former New York Mercantile Exchange President J. Robert "Bo" Collins, shut its doors after losing roughly

half its value in a series of highly leveraged bets on natural gas prices.

RMF Investment Management, a MotherRock investor, recently told its own investors that "there is a strong likelihood that investors will not receive any of their original investment." RMF Investment, a firm that specializes in investing in hedge funds, is a subsidiary of Man Group, the big hedge fund and financial-services conglomerate.

A copy of the Sept. 12 letter, provided to

TheStreet.com

by a source, says that last week MotherRock's primary broker "sold all remaining positions in the fund's portfolio to a third party." But the sale didn't generate enough money to repay the debts that MotherRock owed its broker.

RMF Investment says it doesn't know how much MotherRock still owes its broker.

A spokeswoman for RMF Investment, which is based in Switzerland, did not respond to an email seeking comment. Collins did not return a phone call placed to the hedge fund's New York office.

MotherRock's hedge fund marketing literature had listed

ABN Amro

(ABN)

and

Goldman Sachs

(GS) - Get Report

as the fund's prime brokers. ABN Amro also is believed to have been an investor in the fund, according to sources.

In recent days, other institutional investors have said they are treating their investment in MotherRock as being worthless. PSolve Alternatives recently told investors it is writing down its MotherRock investment to zero. Dexion Alpha Strategies, another European hedge fund investment firm, took a similar step.

The rapid collapse of MotherRock is an indication of just how volatile, and costly, trading in the energy markets can be.

MotherRock, which was formed in December 2004, opened for business in 2005 with high expectations. Collins founded the fund with John D'Agostino, a former Nymex executive, and former Nymex trader Conrad Goerl. Carol Coale, a former Prudential Equity natural gas analyst, had headed up MotherRock's research team.

Before joining the Nymex, Collins was a senior vice president at

El Paso

(EP)

, where he oversaw the energy company's gas trading group.