Gerald Ratner (Family photo / July 2, 2014)

Gerald Ratner practiced law in Chicago for more than 75 years and for many decades represented the billionaire Crown family in business and real estate deals that included the sale of the Empire State Building.

A baseball player at the University of Chicago, Mr. Ratner's name is on the Hyde Park school's $51 million athletic center, which was designed by architect Cesar Pelli. Mr. Ratner provided $15 million for that building and also gave $5 million for an endowed chair at the law school.

"The university has been good to me, and I am trying to be good back," Mr. Ratner told the Tribune in 2006.

Mr. Ratner, 100, died of natural causes Friday, June 20 at his Water Tower Place condominium, said his nephew, Bill Ratner.

Born in the Brighton Park neighborhood on Chicago's Southwest Side, Mr. Ratner was a young boy when his father deserted the family. He was raised in a one-bedroom apartment behind the tobacco and candy shop run by his mother, an immigrant from what today is Belarus.

He graduated at age 16 from Marshall High School, then enrolled at the U. of C., where he was awarded a full academic scholarship and was a switch-hitting outfielder on the baseball team. He received a bachelor's degree from U. of C. in 1935 and a law degree in 1937.

He had started practicing real estate law before serving in the Army during World War II. He also continued to play baseball, drawing the interest of a scout from the Brooklyn Dodgers. Nothing came of it, and in later years he was philosophical about his brush with the big leagues.

"As a lawyer, you can keep going forever, unless you get disbarred," he told the Tribune in 2006. "And lawyers don't need steroids."

Mr. Ratner and law school classmate Benjamin Gould, who died in 1986, formed the firm Gould & Ratner, counting among their clients Chicago's Crown family. Mr. Ratner represented the Crowns on deals including the merger of their company, Material Service Corp., with General Dynamics, and the sale of the Empire State Building in 1961.

"As an adviser, he was an incredibly skilled attorney with a capacious memory, so getting good legal advice and good historical advice were dependable outcomes," said James Crown, president of Henry Crown and Co.

"He specialized in real estate, but he had such an encyclopedic knowledge of my family's business history. He could understand the entities and he could understand how something related to other transactions. He was really like a one-man archive of all the transactions he had seen over his legal career."

Mr. Ratner remained a daily presence at his law firm until he was 99.

"He was so proud of his firm and the people in his firm. He knew them all individually and what they cared about and why they came to Gould & Ratner," Crown said. "He was a great leader."

Reese Elledge, a partner at Gould & Ratner, described Mr. Ratner as a mentor.

"He was a very good lawyer who could write cleanly. People who write cleanly, think cleanly, and he was meticulous in his work," Elledge said. "He also had a great sense of humor, with a twinkle-in-the-eye kind of humor. He did a lot of things to make this firm more familylike."

Gould & Ratner partner Amy Blumenthal said Mr. Ratner was someone who was "interested in everything and everyone."

"He knew everybody at Gould & Ratner — not just the partners and the associates, but he knew every staff member, he knew the cleaning staff, he knew all about our children and for some of us, our grandchildren," she said. "He knew everyone and everybody's families and what was going on in everybody's lives because he really wanted to. He would refer to us as his kids."

In addition to his other donations to the U. of C., Mr. Ratner also gave $1 million to the U. of C.'s Smart Museum for a gallery that was named after his wife, Eunice, who died in 2005.

"He appreciated the opportunities that U. of C. had given to him and as a result of that made some major donations to the university," said Gould & Ratner partner Steve Sandler. "He didn't wait until he died — he did it during his lifetime."

Mr. Ratner told the Tribune in 2006 that he was not shy about attaching his name to his gifts.

"It's a way of saying, 'I lived. I did something worthwhile,'" he said. "I think people should give while they are alive so they can have the satisfaction of giving."

There were no immediate survivors.

Private services were held.