Joe Jamail in 1987. (BRUCE BENNETT/Houston Chronicle via AP)

Joe Jamail, the Texas billionaire who became the richest practicing lawyer in the United States after winning jury verdicts in civil lawsuits that included a $10.5 billion award for Pennzoil in its landmark case against Texacoduring the 1980s, died Dec. 23 in Houston. He was 90.

His death was confirmed by Christopher Roberts, a spokesman for the University of Texas law school in Austin, of which Mr. Jamail was an alumnus and a supporter. The cause was complications from pneumonia, according to the university.

Dubbed the “King of Torts” for his victories against large corporations, Mr. Jamail was lead counsel in more than 200 cases that resulted in verdicts or settlements of at least $1 million for clients in personal-injury matters.

His representation of Pennzoil in a case against Texaco over the purchase of Getty Oil led to a record jury verdict and helped make him one of the U.S.’s most sought-after lawyers during his five decades in practice.

Torts are the basis for many civil lawsuits, ranging from negligence to assault and product liability.

In 1985, a jury in Houston found in favor of Pennzoil, which had filed a lawsuit seeking $15 billion in damages from Texaco, then the third-largest U.S. oil company. Pennzoil claimed Texaco’s 1984 deal to buy Getty had interfered with an agreement that the Houston-based company had in place. The case was settled for $3 billion, with Mr. Jamail’s firm receiving about $345 million in fees.

“It did change the way corporate America conducted its business with other corporations,” Mr. Jamail said of the Pennzoil verdict in a 2011 speech at the Rock Center for Corporate Governance at Stanford University in Palo Alto, Calif.

Mr. Jamail’s net worth was estimated at $1.65 billion, according to Forbes magazine. In 2010, he was cited as the nation’s richest practicing lawyer by the American Bar Association Journal.

He represented clients in cases that resulted in product recalls of the Remington 600 rifle, Honda’s all-terrain three-wheel vehicles and the prescription drug Parlodel. His victory in Coates v. Remington Arms Co., in which his client was a man who had been paralyzed from the waist down when his son’s hunting rifle discharged with the safety lock on, resulted in a cash settlement of $6.8 million in 1978, the largest in tort law history at that time.

The Houston-based lawyer, who counted country singer Willie Nelson and former University of Texas football coach Darrell Royal as close friends, sought cases that could be broken down to basic principles for the average citizen.

Though his courtroom language was often colorful — once described as “vulgar” by the Delaware Supreme Court — he was considered a master at winning over juries by emphasizing the human elements of a case and ensuring the right mix of jurors.

“He’s a shrewd person about weaknesses of people,” Richard Miller, legal counsel for Texaco in its dispute with Pennzoil, said in a 2003 interview with the Dallas Morning News. “He understands human frailty, and that’s a big part of his success; nobody can deny that.”

Mr. Jamail was on the winning side in the $560 million negligence and fraud case U.S. National Bank of Galveston et al v. Coopers & Lybrand et al in 1992. He was also successful for the Hugh Roy Cullen family, one of the richest in the United States, in its 1983 probate fight against two estranged grandsons.

Mr. Jamail was proud to remain a trial lawyer in an era when reliance on mediation and arbitration reduced the number of jury trials and hurt the profession, he told the ABA Journal in 2009.

“By not trying the small cases, the lawyers don’t get the courtroom experience,” he said, according to the ABA Journal. “So when the huge, bet-the-company cases come along, there are only a handful of trial lawyers who can handle it. That’s why these big corporations still call us old-timers every day.”

Joseph Dahr Jamail Jr. was born Oct. 19, 1925 in Houston. His father and uncle ran the Jamail Brothers grocery business, which owned about 20 stores in Texas.

Mr. Jamail attended Blessed Sacrament School, a Catholic-run institution about two blocks from his Houston home, and was the victim of neighborhood bullies from non-religious schools.

“I was a good marble player, so I tied a bunch of marbles in a sock and the next time the bigger boy came at me, I nailed him with that,” he said in a 2007 interview for the Houston Oral History Project. “I think he must have been out a week because nobody bothered me again.”

After more than two years of Marine Corps service in the Pacific during World War II, he received a bachelor’s degree from the University of Texas in 1950. He was awarded a law degree there three years later.

In the 1950s, Mr. Jamail was an assistant district attorney in Harris County, Tex., and founded his own law practice in Houston. It became Jamail & Kolius about 20 years later when he teamed with S. Gus Kolius, who died in 2006. In later years, their legal advice was so in demand that they accepted only one case for every 350 offered to them, Mr. Jamail said.

“I went over 13 years without losing a case,” Mr. Jamail said. “I tried them every week pretty much. So word got out. People began writing about me.”

Mr. Jamail and his wife, the former Lillie Mae “Lee” Hage, donated generously to his law school, where they helped fund more than 10 of its academic chairs, five professorships and half a dozen student scholarships, according to the university. One donation of $10 million was the largest ever received by the school.

His wife, whom he married in 1949, died in 2007. They had three sons.

“Bullies and snobs have always ignited in me the fire that smolders inside my soul,” he wrote in his autobiography “Lawyer: My Trials and Jubilations” (2003). “I have never been able to stand by and let someone abuse another person. I have to go in and help. And win.”

— Bloomberg News