Alan J. Davis, 70, a premier defense lawyer who was lead negotiator in some of the nastier labor disputes in Philadelphia's recent history, died of pulmonary failure yesterday at the Hospital of the University of Pennsylvania. He lived in West Mount Airy.

"Alan was a superb human being. He was honest, fair and a great lawyer," Gov. Rendell said yesterday. "He served Philadelphia enormously well as city solicitor but, most importantly, as counsel during the labor negotiations with city unions in 1992.

"He was the unsung hero. He was the key person who crafted a work-rules and benefits package that helped turn the city around. His death is a tragic loss."

Said former Mayor Bill Green: "There is a hole in my heart today. There is a hole in the heart of the city with the death of Alan Davis.

"Alan led a life that did justice to good motives and great talent," Green added. "The city is clearly losing one of its most talented sons."

Mr. Davis' negotiating style prized victory over compromise in labor negotiations.

"I would like to make love, not war. But that has not been my lot in my public labor career," Mr. Davis said in a 1996 Inquirer article after he was hired as chief negotiator for the school district in talks with the teachers union.

He signaled a hard-nosed approach and a great role for Mayor Rendell in the battle: "I haven't been brought into easy situations. I've been called in at times of crisis."

Mr. Davis was raised in a rowhouse in Strawberry Mansion. His father was a machinist and union organizer, his mother a social worker. He graduated from Central High School in 1953, where he was a chess champion. He earned a bachelor's degree in psychology in 1957 from Penn and a law degree in 1960 from Harvard University, where he was editor of the Law Review.

Mr. Davis began his career with Wolf, Block, Schorr & Solis-Cohen in 1961. One of his cases was defending mob boss Angelo Bruno in a federal racketeering case. Mr. Davis won.

U.S. Sen. Arlen Specter, then Philadelphia's district attorney, lured Mr. Davis away from Wolf Block in 1966. As an assistant district attorney, Mr. Davis came into the public's eye when he prosecuted mob bosses and investigated city prisons.

"Holmesburg Prison is nothing but a factory of crime, where inmates are programmed to commit rape and robbery in preparation of the day they are released," he wrote in a 1968 report on the prison system.

"Alan was the best and the brightest," Specter said. "He joined my D.A. Office in 1966 to be chief of the appeals division, and he made some of the finest arguments in the history of the Pennsylvania Supreme Court."

In 1968, Mr. Davis returned to Wolf Block and defended several high-profile cases, including that of then-City Councilman Isadore H. Bellis, who was accused of violating campaign-finance laws and taking bribes from companies seeking city contracts. Bellis was convicted, but Mr. Davis persuaded a judge to give him probation. He later got the conviction overturned.

In 1980, Mr. Davis again left Wolf Block when he was named city solicitor under then-Mayor Green. In that capacity, Mr. Davis was chief negotiator during contract talks with the Philadelphia Federation of Teachers. The negotiations resulted in strikes in 1980 and 1981.

"Alan was one of the smartest and most decent persons I have ever met," former Mayor W. Wilson Goode Jr. yesterday said. "He was ethical and considerate, and what I think was the epitome of what a public servant should be."

"Alan was a great humanist, broadly erudite and compassionate," said Mark Aronchick, former chancellor of the Philadelphia Bar Association and former city solicitor, who was mentored by Mr. Davis. "He imparted a passion for the law and encouraged me. Alan was like my big brother."

In 1983, Mr. Davis left the City Solicitor's Office and returned to Wolf Block. That year, SEPTA contracted him to be its chief negotiator during talks with the union representing Regional Rail system workers. The talks resulted in a four-month strike. In the end, SEPTA achieved most of its goals, eliminating 600 union jobs, jettisoning what it considered antiquated work rules, and reducing some salaries.

Mr. Davis left Wolf Block in 1991 and became a partner in another high-profile firm, Ballard, Spahr, Andrews & Ingersoll.

In 1992, Rendell asked Mr. Davis to be his chief negotiator in bargaining with the city's unions. Mr. Davis did much of the negotiating for free. A contract in which the unions made many concessions was reached after a one-day strike.

In 1996, he again negotiated with the teachers union, this time at the behest of Rendell. A contract was approved with a provision that denied raises to teachers who were rated unsatisfactory.

"Those of us who were friends with Alan Davis were honored. For the rest of my life I will think of him every day," lawyer Richard Sprague said yesterday. "Our last visit was on Saturday in the hospital. He knew he was dying. He was not angry about it. He accepted it. We kissed goodbye."

"He was my encyclopedia, history books and teacher," said his wife of 39 years, Lyn. "During a conversation about the upcoming mayoral race in the hospital, he explained the history of each candidate and why one was taking cracks at the other."

On April 14, she and her husband left for the Caribbean. "We vacationed for a week in the Turks and Caicos Islands when he fell ill," she said. "When we returned to Philadelphia, he was soon hospitalized."

In addition to his wife, Mr. Davis is survived by a son, Michael; a daughter, Jennifer Ulrich; two granddaughters; and a brother.

A funeral service will begin at 11 a.m. tomorrow at Goldsteins' Rosenberg's Raphael-Sacks, 6410 N. Broad St. A reception will follow at the Germantown Jewish Center, 400 W. Ellet St., Mount Airy. Burial will be private.

Contact staff writer Gayle Ronan Sims at 215-854-4185 or gsims@phillynews.com.