Frank Sugrue trailed the tip of a finger around the rim of the Bloody Mary he was sipping at the Ritz one afternoon in 1969 and mused about the path that led him from law school to running the Charles Playhouse, one of the nation’s first premier regional theaters.

The soaring financial highs and plummeting lows of producing plays had placed him in a far different venue than a courtroom, but he said there were advantages to being a non-practicing lawyer. “Through all the hassling we’ve had, all the troubles, worries, fears, I guess maybe my background in the law has kept me out of jail,’’ he said with a nervous smile as he spoke with Kevin Kelly, the Globe’s theater critic.

Mr. Sugrue, who was 90 when he died Wednesday in the Bostonian nursing center in Dorchester of complications from dementia, led a life that was as dramatic as any play he produced in his theater on Warrenton Street.

While on a run with a successful production, he might pull up to the Charles Playhouse in an expensive sports car, clad in elegant suits. He took evasive action, though, if a play was a dud, theater seats grew empty and cold, and money was suddenly scarce.

“Frank had a little trapdoor in his office that he could climb into to hide when the bill collectors came – that’s the truth,’’ said Roger Farrington, who formerly worked for Mr. Sugrue in a variety of capacities, including as in-house photographer, from 1975 to 1980.

Mr. Sugrue and his then-partner, Michael Murray, cofounded the Charles Playhouse in the late-1950s. They moved an acting company from its original home – a loft above a Charles Street fish market – to more spacious quarters in an abandoned nightclub on Warrenton Street, and kept “Charles’’ as part of the name as a reminder of the company’s past.

Together, Mr. Sugrue and Murray – the playhouse’s artistic director for its first decade or so – launched Boston’s Off-Broadway theater movement. The names of actors who spent at least part of their early careers performing at the Charles varies, depending on who’s doing the remembering, but their numbers have been said to include Jane Alexander, Ned Beatty, John Cazale, Stockard Channing, Jill Clayburgh, Swoosie Kurtz, and Al Pacino. Ian McKellen was among other well-known actors who took to the stage at various points during Mr. Sugrue’s tenure, which lasted until he sold the playhouse to theater producer Jon B. Platt in 1995.

Mr. Sugrue “was a delight to be with – when he wasn’t thinking about money and paying his bills,’’ said Smoki Bacon, a longtime friend who assisted him with marketing at one point. “When you’re in the theater business it’s an up and down situation. You may have a hit one week, but there’s no such thing as a sure thing. Frank was a master of keeping the playhouse going, even when there wasn’t any money coming in.’’

Described by a Globe reporter in 1985 as “arguably Boston’s biggest theatrical asset,’’ Mr. Sugrue could be as show-stopping off-stage as his actors were on it.

“Frank had three loves: theater, ladies, and the Patriots, and I would say it was in that order,’’ said Joanna Datillo, a filmmaker and longtime friend. “The other thing is that he never met a neighborhood bar that he didn’t like. He was famous for hanging out at them. Also, there was no alcohol he didn’t like.’’

Datillo, who was Mr. Sugrue’s power-of-attorney, was in college when she met him. “I remember him wearing three-piece suits and driving around in a big old wonderful green Jaguar,’’ she recalled.

Such a regal presence was a far cry from his beginnings. One of six siblings, Mr. Sugrue was a son of Dennis Sugrue and the former Margaret Downing, both immigrants from County Kerry, Ireland.

“He was always very proud of being from a blue-collar family and moving so far ahead culturally,’’ Datillo said. “He always told me he learned which forks to use from his girlfriend on the North Shore. He never tried to hide where he came from.’’

Mr. Sugrue told the Globe in 1981 that his father was a locksmith: “He went around repairing locks on bathhouses, like at L Street, Carson Beach. When I was a kid of about 5, I used to go with him.’’

While growing up in Dorchester, Mr. Sugrue “bounced around as a football bum’’ from one school to the next before he enlisted in the Marine Corps at 17. Stationed in the city in China then known as Tientsin, he inadvertently found his future calling.

“I was reassigned to a Special Services unit; all the athletic assignments had been given out,’’ he said in 1981. “My job was to put together entertainment for the troops. We opened an old movie house in the city, showed movies borrowed from the Navy, arranged shows. The first legitimate production I did was ‘Arsenic and Old Lace.’ It’s a little odd to remember that my introduction into the world of theater came through a couple of Marines in drag and fright wigs, playing two crazy old ladies, but that was it. I was really only biding time before being shipped home. Somehow, the show-business bug bit.’’

Afterward, Mr. Sugrue finished high school and received a bachelor’s degree in economics from Boston University. In 1956, he graduated from the Northeastern University School of Law. Within a year he met Murray, “and we started the Charles above the fish market,’’ Mr. Sugrue recalled. “The truth is I had no idea my career would end up in the theater. I should have known better!’’

A private burial at Massachusetts National Cemetery in Bourne will be held for Mr. Sugrue, who also had lived in Palm Beach, Fla., and had no immediate survivors, Datillo said.

His three marriages ended in divorce. The third was to Roberta Kosloff, who “was Frank’s true love,’’ Farrington said. Mr. Sugrue was very close to her and her two children from a previous marriage, Aaron and Kimberlee, Datillo added.

Mr. Sugrue first met Roberta in the Charles after a “Shear Madness’’ performance. “We talked in the lobby, went to a party, and that’s it,’’ he told the Globe in 1985.

The Charles Playhouse building on Warrenton Street housed multiple venues: the main theater, which seated more than 500 patrons; a smaller cabaret theater; and a performance space by the bar that was the Comedy Connection’s original home. At times, the operation ran on a prayer and a phone call.

“Frank kept the theater going at all costs because it was his life,’’ Farrington added. “He loved it, and he believed that Boston needed an intimate, 500-seat theater for top shows with top talent.’’

If utility late-payment notices piled up, Farrington added, Mr. Sugrue would call in a favor from a power company acquaintance to keep the electricity switched on so he could run one more show and pay his bills.

“I’m not an artist, I’m a businessman, and I love the whole concept of managing a show all the way through to opening night,’’ Mr. Sugrue said in 1981. “I’ve always found that exciting – still do.’’

Bryan Marquard can be reached at bryan.marquard@globe.com.