Deak & Co. and two of its internationally oriented subsidiaries filed for bankruptcy reorganization yesterday in New York, but Deak-Perera U.S. Inc., the retail and wholesale precious metals and currency firm that operates offices throughout the United States, remains healthy, Deak officials said.

Deak-Perera officials said that as far as they can determine, the two subsidiaries that filed Chapter 11 reorganization along with the parent company did no business with U.S. citizens. Most of their customers were in South America.

Deak & Co., directly and indirectly, owns Deak-Perera U.S. as well as several other subsidiaries that are unaffected by yesterday's reorganization filing.

Deak-Perera U.S. is a "good, healthy, profitable, viable company," said Leslie Deak, president of the big U.S. precious metals and currency company. The reorganization merely means that the profits of Deak-Perera U.S. will go to the benefit of Deak & Co. creditors. Otherwise, Deak-Perera operations will not be affected, he said.

Deak said that the parent company and two of its subsidiaries -- Deak-Perera Wall Street and Deak-Perera International Banking Corp. -- fell prey to adverse publicity the companies received in South America as a result of U.S. Crime Commission testimony earlier this year -- although the testimony did not accuse Deak of doing anything more than failing to file a proper form with the government. Deak paid a civil penalty for the 1978 omission.

Nevertheless, Deak said, the testimony received wide publicity in South America, and many of the firm's customers withdrew their investments. That led to cash-flow difficulties in the two subsidiaries. He said the withdrawal problems were compounded by the sharp rise in the value of the dollar, which reduced the value of a foreign bank owned by the subsidiaries.

Deak said that Deak-Perera U.S.'s business, including its precious metals storage program, will continue normal activities. He said customer metals are completely segregated from other company assets and are held in independent depositories. He said a 1984 audit of the program was just completed.

Besides Deak-Perera U.S. Inc., other unaffected subsidiaries of Deak & Co. are Deak-Perera Securities Inc. and Deak-Perera Futures. Deak National Bank, based in New York City, is independently owned and also unaffected by Deak & Co.'s Chapter 11 filing.