He could face up to five years in jail when sentenced on June 22.
According to court papers, Chait – son of company founder Isadore Chait – falsified customs forms for overseas clients by stating that the CITES-controlled items were made of bone, wood or plastic.
During New York Asia Week in 2011, Chait was approached about the potential sale of a rhino horn carving of the deity Guanyin.
Despite knowing that it was not an antique, Chait accepted the consignment, put it on the cover of the firm’s September Asian sale catalogue and advertised it to clients in China.
After the rhino carving sold at auction for $230,000, Chait offered to make an invoice for the buyer stated that the item was plastic and cost $108.75.
The US Justice Department said the value of similar transactions listed in court papers totalled at least $1m.
The case matter is part of Operation Crash, a continuing investigation by the US Fish and Wildlife Service into the unlawful trafficking of rhinoceros horns.
Assistant attorney general John C Cruden stated: “Those in the auction industry need to be responsible and not turn a blind eye to the fact that trade in protected animal parts is highly regulated.”