Michael J. Izzo Jr., 68, of West Deptford, a senior partner in the Cozen O'Connor law firm whose melodious tenor filled courtrooms and concert halls for four decades, died Sunday, Dec. 9, of complications of leukemia at Thomas Jefferson University Hospital in Philadelphia.

When he joined Cozen O'Connor in 1973, he became only the sixth lawyer in the then-small Center City practice. The firm would grow to nearly 600 lawyers in 22 locations, and Mr. Izzo's reputation as a consummate practitioner would burgeon with it.

He was known for pulling settlements of tens of millions of dollars from complex litigation, frequently involving product liability and catastrophic property damage. The record-breaker came in a civil suit involving a 1985 fire that devastated the industrial core of Passaic, N.J. He wrested $60 million for the plaintiffs - the largest settlement of a fire case in New Jersey history.

In federal and state courts in New Jersey and Pennsylvania, he "was a force to be reckoned with," said Joseph A. Gerber, long a colleague at Cozen O'Connor. "He was a relentless advocate for clients, but maybe more important, he earned the respect of the judiciary and opposing counsel.

"You either respected him going in, or you learned to respect him the hard way."

Gerber met Mr. Izzo in 1969, when they were law clerks, and wound up as his office neighbor for years. That put him within earshot of Mr. Izzo's vocalizing as he practiced for performances with the Orpheus Club of Philadelphia, the oldest men's singing society in America.

"He'd perform for you at the drop of a hat. If you met him in the hallway and asked how 'My Mammy' went, he would crouch down, put his arms out and sing it," Gerber said. "He put the same enthusiasm and seriousness of purpose into all pursuits."

The only child of a blue-collar family in Englewood, N.J., he attended St. Peter's Prep in Jersey City, where he played baseball, and then went to St. Peter's College, where his interests turned to the glee club. Graduating in 1966 with a degree in English, he enrolled in Villanova University School of Law, where he was a member and editor of the Law Review in his last year, 1969.

For the next two years, Mr. Izzo clerked for U.S. District Judge E. Mac Troutman of the Eastern District of Pennsylvania. He worked briefly at Clark Ladner Fortenbaugh & Young before joining Cozen O'Connor in 1973.

In a few years, he was a senior partner. As part of the subrogation litigation division, he argued some of the firm's largest verdicts - including one for $32.3 million in a sprinkler design case and another for $30.6 million in an insurance reformation and breach of contract case.

He was regarded as both a compelling legal writer and oral advocate at the trial and appellate levels, winning a favorable ruling from the U.S. Supreme Court in 2005 in a long-running case involving the energy giant O'Brien Cogeneration Inc.

As much as he loved the law, he also loved choral music, said his wife of 41 years, Janet.

When he discovered the Orpheus Club 30 years ago, he embraced it as a fraternity. "The members became his brothers," she said. "That was his life."

From September through May, he rehearsed weekly with the chorus for three concerts at the Academy of Music. He also performed with the club's parodic group, the Twelfth Night Revels. And he was on the board of directors of the annual Sylvan Opera Festival in the Pennsylvania suburbs.

"He was pretty much a self-made man," his wife said, and so found pleasure in the finer things - from Porsches to exquisite fabrics and golfing - that flowed from his career.

He was long a member of the Bacchus Society, a philanthropic group dedicated to the appreciation of wine and great food.

In addition to his wife, Mr. Izzo is survived by daughters Caren and Jeannine; son Michael; and two grandchildren.

A viewing will be held from 6:30 to 9 p.m. Thursday, Dec. 13, and 10 to 10:45 a.m. Friday, Dec. 14, at Holy Angels Parish (St. Patrick's Church), Cooper Street, Woodbury. A Funeral Mass will follow at 11. He will be interred in Eglington Cemetery, Clarksboro.

Donations may be made to Villanova University School of Law, 299 N. Spring Mill Rd., Villanova, Pa. 19085, or the Leukemia Society and Lymphoma Society of Eastern Pennsylvania, 555 North Lane, Suite 5010, Conshohocken, Pa. 19425.