El Al said on Thursday it has been ordered to testify before a grand jury in a U.S. government investigation of possible price-fixing violations in air cargo transport.In a statement to the Tel Aviv stock exchange, Israel’s largest carrier said it had received a subpeona to appear before a grand jury in Washington on November 1 and to produce documents relating to the price-fixing suspicions.

According to El Al, the U.S. Justice Department has been carrying out a price-fixing investigation of the cargo operations of several other airlines over the past few months.