Another Ousted Warner Exec Is Expected to Sue Company : Music: Melvyn Lewinter, dismissed last week, would claim breach of contract. Firm says he was fired for cause.

In the latest twist in the corporate uproar at Warner Music Group, another of the firm’s ousted top record executives is expected to file a $15-million breach-of-contract suit today against the nation’s largest music conglomerate.

Melvyn R. Lewinter, former president and chief operating officer of Time Warner’s domestic music division, was abruptly fired Wednesday--exactly five weeks after his boss Doug Morris got the boot. Lewinter, a 25-year company veteran with more than four years remaining on his contract, is the sixth music honcho to exit the firm in the past 13 months.

“Mel is outraged,” said Edward Spiro, a New York attorney representing Lewinter in the case. “It is shameful for a respected executive to be treated so shabbily after 25 years of loyal service.”

On Wednesday, Warner Music Group Chairman Michael Fuchs told Lewinter he was fired “for cause,” in Fuchs’ words, leading sources to speculate that the dismissal may be connected to an internal inquiry into improper sales practices at Warner-owned Atlantic Records.

The dismissals come at a time when the music division is dominating the pop charts. The $4-billion conglomerate, which includes the Atlantic Group, Elektra Entertainment Group and Warner Bros. Records, has almost twice the market share of its nearest competitor.

Morris was fired after his boss, former Warner Music Group Chairman Robert Morgado, was ousted in May after a highly visible power struggle with Morris. Morgado reportedly negotiated a $40-million settlement with Warner. A power struggle between Morgado and Warner Bros. Music heads Mo Ostin and Lenny Waronker forced their exit earlier this year.

Elektra chief Robert Krasnow quit last year after a dispute with Morgado and received a $7-million settlement.

In addition, Time Warner discharged 10 employees between December and March after thousands of Atlantic compact discs were alleged to have been stolen and sold on the sly to retailers.

Sources said Nick Maria, one longtime sales chief who was terminated without a severance package in December as a result of the investigation, was contacted recently by Time Warner attorneys and interviewed by them several times regarding the scandal.

Time Warner could use information provided by Maria and several other dismissed employees to bolster their cases against Lewinter and Morris, who filed a $50-million wrongful termination suit against the company in June.

Allegations made by Maria could show up in court as early as Tuesday, when Time Warner’s attorneys are scheduled to file an answer to Morris’ suit.

Maria, sources said, recently received an estimated $200,000 severance settlement with Time Warner that is said to include a long-term health benefits package.

A spokesman for Time Warner declined to comment further. Representatives for Maria were unavailable.