The president of Emersons Ltd. resigned yesterday as the steak house chain approached a critical junction in its trip back from bankruptcy.

Steve Rubell, a partner in New York's Studio 54 disco, and David Geffen, former chairman of Elecktra Asylum Records, are negotiation for control of Emersons.

William Story, 43, president of Emersons since June, said he had planned for some time to quit by the end of the year, anticipating that an agreement would be reached with Rubell and Geffen.

Last fall Rubell and Geffen acquired about 28 percent of Emerson's outstanding stock by paying the company $50,000 for 500,000 shares held by the company.

Now Rubell and Geffen are seeking to increase their ownership to at least 49 percent by investing additional funds that would enable Emersons to complete Chapter XI bankruptcy proceedings.

Story said Rubell and Geffen have offered to provide the cash necessary to pay Emerson's unsecured creditors 7.5 cents on each dollar of debt and to provide up to $500,000 in additional working capital for the steak house chain.

A plan of arrangement detailing the offer to creditors has been filed in federal bankruptcy court in Maryland, said Alan Kerxton, the attorney handling the bankruptcy.

Although 7.5 cents on the dollar is a small settlement even by Chapter XI standards, sources familiar with Emersons' financial problems said it is probably more than the unsecured creditors would get if the chain were liquidated.

Most of Emerson 23 steak houses are pledged as collateral on loans from Fidelity Bank of Philadelphia, which would have first claim on any funds raised by selling the stores.

Kerxton said the bankruptcy plan would give fidelity Bank $112,500 in cash and a 10-year note for $2 million.

Emersons owes its unsecured creditors $13 million and Geffen and Rubell would provide the cash for the 7.5 percent settlement. That plan has not yet been presented to the creditors committee because the deal with Geffen and Rubell is not completed.

Story said negotiations were halted recently after the Internal Revenue Service agents, armed with search warrants, raided Studio 54 and carted off financial records and a quantity of cocaine that was allegedly found in the safe of the disco.

Although Rubell and Geffen are seeking control of only 49 percent of Emersons stock, that would probably be enough for them to engineer a merger with another firm. A corporation merging with Emersons would be able to utilize $13 million in federal income tax credits that Emersons accumulated from past losses.

Emersons itself has little prospect of generating enough profits to use the tax credits before they expire in five years, Story said.