Computer Associates International Inc is ready to get tough in its continuing attempts to acquire services company Computer Sciences Corp. It is already seeking regulatory approval of the proposed deal. The Islandia, New York software giant sent a clear sign of its determination by filing a Hart Scott Rodino Premerger Notification with the US Department of Justice and the Federal Trade Commission. In a move that could be seen as a power play to put more pressure on CSC and its shareholders, CA says it has notified CSC of the filing, which is required of any planned merger. The filing comes only a day after CSC insisted it had not had any real discussions with CA and that any talk of a pending merger or acquisition is clearly false. CSC chief executive Van Honeycutt is reportedly seeking another suitor to block the CA bid and IBM Corp, AT&T Corp and EDS Corp have all been contacted, according to Reuters. Meanwhile, certain CSC shareholders have filed a class action complaint against the company which also names CA as a defendant.