David Berger, 94, a prominent trial lawyer from Philadelphia best known for winning settlements in several high-profile class-action lawsuits, died of complications from pneumonia Feb. 22 at a hospital in West Palm Beach, Fla.

Mr. Berger, a self-described "people's lawyer," was one of the first in his field to use in federal court the legal mechanism known as class action, by which small injuries are pooled together and pursued in a single legal action.

He started in the 1960s and continued to practice law until retiring from his Philadelphia law firm in 2004.

In a list published in an Associated Press article in 1985, Mr. Berger's cases included a $2.5 billion settlement from the government on behalf of the bankrupt Penn Central Railroad and thousands of its shareholders; a $25 million settlement for residents of the Three Mile Island area against General Public Utilities, owner of the nuclear power plant; and a $25 million settlement from 13 of the biggest U.S. oil companies on behalf of 30,000 gasoline station operators.

He also represented schools in lawsuits against asbestos manufacturers and municipal governments against rock salt suppliers.

In response to critics of big-ticket litigation, Mr. Berger pointed out that he collected fees only if he won. Aside from that, he regularly declined to discuss his personal finances.

In the Associated Press article, Mr. Berger said his motivation was "to use the law as an instrument of change."

"Over the years, I've come to the decision that the class action is a very fine basis for doing that," he said. "There's no way in the world that a small shareholder can bring suit against the corporation and its directors for failing to disclose true information about the firm."

Early in life, Mr. Berger showed a tenacity and resourcefulness that would become hallmark characteristics of his legal career as he took on the federal government, public utilities and large corporations.

He was born in Archibald, Pa., and worked his way through college after his family struggled in the Great Depression. He distinguished himself at the University of Pennsylvania Law School, where in 1936 he graduated first in his class.

After law school, he clerked for the Pennsylvania Supreme Court and the U.S. Court of Appeals for the 3rd Circuit.

In World War II, he joined the Navy and served in the Pacific aboard the aircraft carrier USS Hornet. He attained the rank of commander and received the Silver Star.

He served as Philadelphia city solicitor before returning to private practice.

His marriages to Harriet Berger and Barbara Berger ended in divorce.

Survivors include two sons from his first marriage, Daniel Berger and Jonathan Berger; two brothers; and two grandchildren.