Excite@Home Corp., the No. 1 U.S. provider of fast Internet service, countersued Cablevision Systems Corp. seeking monetary damages and the cancellation of its warrants owned by the cable provider. The counterclaim was filed Friday, the same day that Excite, AT&T Corp., Comcast Corp. and Cox Communications Inc. answered a suit by Cablevision in Wilmington, Del., Cablevision said in a Securities and Exchange Commission filing. Cablevision, based in Bethpage, N.Y., didn't say how many warrants it owns or what damages Excite is seeking. Officials at Redwood City, Calif.-based Excite weren't available to comment. Cablevision sued to block AT&T's March 28 deal to buy out Comcast and Cox's stake in Excite, saying it should have been included because it's an investor. Cablevision says the agreement violates Excite's corporate charter, which requires that all partners agree before one company can assume control of Excite. Excite and its partners have said they did nothing wrong. Cablevision rose $2.14 to close at $70.06 on NYSE; Excite closed down 38 cents to $20.38 on Nasdaq.