Two top executives of a conglomerate, with the help of a stockbroker, manipulated the price of their corporation's stock upward in order to use the inflated shares to acquire new companies, according to a federal suit filed yesterday.

In a civil complaint filed in U.S. District Court in Manhattan, the Securities and Exchange Commission named Chromalloy-American Corp., Joseph Friedman, its chairman and chief executive officer; Lawrence J. Manning, a Chromalloy vice president; and Jacob Schaefer, a registered representative with Evans & Co. in New York City.

Simultaneous with the filing of the suit, the defendants consented to the complaint without either admitting or denying the allegations.

According to the complaint, beginning in March 1973 and continuing into August 1976, the St. Louis firm acquired in excess of 1 million shares of its own common stock.

Much of the stock was sold to key employees of Chromalloy at preferred prices, with the company paying 50 per cent of the price.

Manning and Friedman, who handled the stock acquisitions, were in constant communication with Schaefer, the broker who was monitoring the Chromalloy stock.

The SEC said: "Manning and Friedman . . . placed orders in such a manner so as to frequently cause Chromalloy common stock to close at the end of the trading day at a higher price than the prior sale price, thereby 'upticking' the price."

They placed 95 per cent of these orders through Schaefer, and would arrange to buy all the Chromalloy stock available for sale at the end of a trading day, the SEC said. Then they would place an additional order at a slight increase in price, causing the stock to close higher.

By this process, the SEC said, Chromalloy's common stock closed on an "uptick" on approximately 298 of 424 trading days between Jan. 1, 1975, and Aug. 31, 1976.

Chromalloy, with sales of $791 million in 1976, has a broad array of subsidiary companies whose products range from steel facricating and menswear to glassware and farm equipment.

The SEC complaint states that some of these companies were paid for with chromalloy stock that had been artifically inflated.

As a part of the civil fraud charges, the SEC said that "Chromalloy acquired the assets of other companies with . . . common stock and convertible preferred."

An SEC source said that the stock during this period was pushed up to about $15 a share. The commission does not name the companies that were acquired during the period in question.

According to the SEC source, the division of enforcement detected the unusual trading pattern in Chromalloy stock through routine surveillance procedures.

Chromalloy's stock is traded on the New York Stock Exchange.