he messy battle between the Texas billionaire Sam Wyly and Computer Associates became a bit messier yesterday when Mr. Wyly sued the company in response to a lawsuit that Computer Associates had filed against him earlier.

In yesterday's countersuit, filed in federal court in Brooklyn, Mr. Wyly accused Computer Associates of violating securities laws by making false or misleading statements about its financial results and relationship with its customers. Mr. Wyly also contended that Computer Associates did not disclose to its shareholders that Roel Pieper, one of its directors, had been chairman of Lernout & Hauspie, a bankrupt Belgian software company that was found by its auditors to have overstated its revenue.

Computer Associates dismissed Mr. Wyly's claims. "He's trying to win a proxy battle with sound bites," said Sanjay Kumar, the company's president.

Computer Associates, the world's fourth-largest independent software maker, based in Islandia, N.Y., has traded insults with Mr. Wyly since June, when Mr. Wyly began a proxy fight to oust the Computer Associates' board and seize control of the company.

Unlike many would-be corporate raiders, Mr. Wyly is not putting up any money to buy Computer Associates outright. Instead, he hopes to persuade existing shareholders that he can do a better job running the company than its current management.

Mr. Wyly, who sold his company, Sterling Software (news/quote), to Computer Associates for $4 billion last year, accuses Computer Associates of alienating its clients, mistreating its employees and overpaying its top executives. He argues that a controversial accounting change Computer Associates introduced last October has made it impossible for investors to understand the company's financial statements.

Computer Associates argues that its sales are strong and improving and that Mr. Wyly's plan to split the company into four independent divisions would deprive it of the scale that has enabled it to compete effectively. It also notes that at other companies he has headed, including Michaels Stores (news/quote), Mr. Wyly has faced criticism for overpaying himself at the expense of independent shareholders.

The dispute between Mr. Wyly and Computer Associates has not exactly grabbed Wall Street's attention this summer, in part because Mr. Wyly is not offering to buy out shareholders. In addition, Walter Haefner, a Swiss billionaire who owns 21 percent of Computer Associates, declared his support for the company's management soon after Mr. Wyly began his takeover attempt. Mr. Haefner's support for management, along with top executives' 7 percent stake in the company, means that Mr. Wyly cannot win unless he persuades more than 70 percent of the company's other shareholders to vote for him.

But that has not stopped Mr. Wyly and Computer Associates from trading insults in full-page newspaper ads and lawsuits. And like a low- grade summer cold, the back-and- forth is all but certain to continue until Aug. 29, when shareholders will have a chance to vote.