Falstaff Brewing Corp. yesterday agreed to a court that will postpone its annual meeting of stockholders, planned today in San Francisco.

The beer company's action was in response to an injunction sought by the Securities and Exchange Commission, which alleged that Falstaff filed "false and misleading" public reports related to a 1975 acquisition of 52 per cent of the firm's stock by company chairman Paul Kalmonovitz.

In other developments:

The SEC charged Forest Laboratories, Inc., a New York pharmaceutical company, with falsely inflating its revenues by $4 million, creating fictitious invoices and recording purported payments for "fictitious research and development work." The company signed a consent order to prohibit such activities in the future without admitting guilt or innoncence.

Internal Revenue Service commissioner Jerome Kurtz said his agency's study of possibly illegal slush funds at American corporations, started in APril 1976, found the existence of 481 funds - of which 71 may represent criminal fraud. IRS questionnaires went to 1,200 firms, of which 896 were answered by the end of March. Kurtz told R. Gregory Nokes of the Associated Press.

In the Falstaff case, U.S. District Court Judge Howard Corcoran ordered that today's meeting be postponed until the court decides the merits of an SEC request for an injunction against the brewing firm. An SEC staff member said Corcoran will conduct a hearing in the case July 8.

The SEC charged that proxy material sent out for today's meeting is "materially false and misleading" in connection with a proposed change in the dividend rights of Falstaff's preferred stock, of which chairman Kalmanovitz owns 100 per cent.

According to the SEC complaint, Falstaff and Kalmanovitz "have been involved in fraudulent conduct" with respect to Kalmanovitz's gaining control of a majority of voting rights in the firm.

For example, the SEC alleged, the company did not disclose that one-half of his voting rights were obtained in consideration for an extnesion of credit from a Falstaff supplier. Falstaff officials did not respond yesterday to a request for reaction to the allegations.

Forest Laboratories said it had uncovered the questionable practices alleged by the SEC through an internal investigation, after an initial inquiry by the regulatory agency. A number of officers who participated in the alleged inflation of revenues are no longer with the firm.

Under the SEC consent accord. Forest has hired a team of investigators headed by Harvard Law Prof. David Hurwitz to conduct a further study and report to its board and the SEC by the end of the year.

Kurtz of the IRS told the AP that 71 cases of possible criminal fraud related to corporate slush funds have been turned over to the agency's intelligence division for further study. Most of the companies involved have total assets of more than $250 million.

The IRS chief said the study will be continued but he indicated that some questions sent to companies may be altered.