Bethesda Research Laboratories Inc., which recently laid off approximately one-third of its work force and has experienced cash-flow problems, has raised $1 million in "bridge" financing, its president said yesterday.

Stephen C. Turner said that most of the money was provided by the company's original investors.

Michelle Hartz, a spokeswoman for the company, said the loan was designed to help alleviate the company's immediate cash-flow problems. Besides laying off workers, the company has restructured some of its divisions and is re-evaluating a move to new headquarters in Frederick, Md.

The intermediate financing was arranged on Feb. 19, the day after the layoffs. The company expects to close on additional financing in the near future, said Hartz, who said the bridge loan is to carry it to that point. She said she could not disclose whether the bridge loan was for a specified period of time.

The company is a biotechnology concern that was founded in 1976 with three employes and that grew rapidly. Sales last year were $10 million, and, before the layoffs, the company had 410 workers.

The company also elected two new members to its board of directors--Frederick R. Adler, a senior partner of the law firm Reavis & McGrath; and William H. Janeway, a vice president and director of corporate finance for F. Eberstadt & Co. Inc. Eberstadt & Co., an investment banking firm, is one of several companies that have helped BRL search for capital.

Adler, who is a founder and chairman of the executive committee of Data General Corp., was elected chairman of BRL's executive committee.