The legal war between the International Securities Exchange (ISE) and the Chicago Board Options Exchange (CBOE) has stepped up a gear with the filing of a second patent infringement suit against CBOE by the ISE.
The latest legal challenge was filed by the ISE Wednesday, in which it claimed that the CBOE had infringed on its patent for trading derivatives securities.
The ISE and CBOE are already involved in a legal tussle over the listing of index options on the S&P 500 Index and the Dow Jones Industrial Average (DJX options). CBOE currrently has an exclusive licence to trade options on the S&P 500 and the Dow Jones Industrial Average.
The CBOE has declined to comment on the latest spat. But, in a memo to membership on its Web site, the exchange said it plans to mount a "vigorous" defense against this "meritless claim."