Updated from 4:58 p.m. EDT

Another major shareholder of

Computer Associates

(CA) - Get Report

came out Friday opposing Sam Wyly's bid for five seats on the software maker's board of directors, offering more evidence that the Texas investor faces an uphill battle.

In a letter filed with the

Securities and Exchange Commission

, Private Capital Management President Gregg Powers said it is urging Ranger Governance, an arm of Wyly's investment firm, to call off its proxy contest and for CA shareholders to oppose a dissident slate of five candidates for the 11-member board of directors.

Naples, Fl.-based Private Capital Management owns 33.9 million shares, making it the second-largest institutional shareholder of CA with about 5.9% of outstanding shares. PCM's letter was addressed to Fidelity Management, CA's largest institutional shareholder.

"PCM supports Computer Associates current board and management," Powers said in the letter. "PCM believes that Ranger's initiation of this proxy contest is without merit, self-serving to the detriment of shareholders, and nothing more than an attempt to confuse, distract and stagnate the operations and progress of Computer Associates."

Powers declined further comment. PCM's letter comes on top of prior support for Computer Associates' management expressed by the company's largest single shareholder, Swiss billionaire Walter Haefner, who owns about 20% of the company's shares. PCM and Haefner's support means that just over one quarter of the outstanding shares already are likely to be voted in favor of Computer Associates management.

Wyly, who unsuccessfully waged a similar proxy

battle last year, announced his latest move Thursday to unseat top management, which Wyly also wants removed from the company. Ranger cited the company's declining stock price and ongoing

investigations by the SEC and U.S. Attorney's office into various accounting practices.

"Ranger expects to talk to all major shareholders over the next two months, including Private Capital, and we believe we will make a very persuasive case for change at Computer Associates," Ranger Governance spokesman Farrell Kramer said in response to Private Capital's letter.

In his letter, Powers said PCM believes the Computer Associates board and management should investigate the origin of the SEC inquiry and vaguely suggested wrongdoing against CA. "We are very concerned that the SEC inquiry may have been precipitated without justification or reasonable basis by parties outside the SEC to serve a personal agenda that is contrary to the public interest and that is detrimental to the company and its shareholders," he wrote.

Shares of Computer Associates declined 36 cents, or 2.2%, to $15.89 in trading Friday.