Lawyer Opened Lines for Phone Company Breakup

Sidley specialized in representing businesses in regulated industries, such as railroading and electric utilities. Satisfying the government’s demands to end AT&T’s permitted monopoly over service was particularly difficult, Mr. Trienens’ colleagues said. The company had argued for years that dismantling the network would jeopardize the quality of local phone service that AT&T supported with profits from its long-distance phone business. But battling the government’s antitrust case against AT&T would likely take years of federal court litigation with an uncertain outcome.

Mr. Trienens, who died July 26 at 97 years old, eventually advocated for the voluntary separation of AT&T’s regional telephone companies. Divesting these highly regulated providers of local phone service, known collectively as the Baby Bells, would leave AT&T with its long-distance calling service, its equipment-manufacturing business and the freedom to pursue new businesses in computers and cable television.

By 1984, AT&T had reached a consent decree with the federal government that created seven new regional phone companies hived out of the Baby Bells. The deal set the stage for the creation of the current telecommunications industry, Mr. Trienens’ colleagues said. One of the regional operators, SBC Communications Inc., later bought its former parent and took its name, creating the modern AT&T Inc.

“Howard was a man of great practical judgment. He was renowned as a person at AT&T that saw the big picture,” said

Martin Lipton,

a partner at Wachtell, Lipton, Rosen & Katz law firm in New York who worked with Mr. Trienens at AT&T.

Mr. Trienens was raised in Wilmette, Ill., a suburb north of Chicago. He was one of two boys whose father was a buyer for drugstore chain Walgreens. He earned a bachelor’s degree from Northwestern University in Evanston, Ill., after serving in the army during World War II and graduated from Northwestern’s law school in 1949. He became a partner at Sidley by the mid-1950s.

After six years at AT&T, Mr. Trienens returned to Sidley, where he had maintained his position as chairman of the executive committee that managed the firm. Mr. Trienens guided Sidley’s growth into a national firm with offices in other cities starting in the 1970s. The firm eventually added offices overseas as well.

“We could see that clients were doing business everywhere,” said Newton Minow, whose firm, Leibman, Williams, Bennett, Baird & Minow, merged with Sidley in 1972. The merger broadened Sidley’s corporate client base into consumer products, advertising, media and real estate.

Messrs. Trienens and Minow had known each since attending law school together. The two clerked for Supreme Court Chief Justice Fred Vinson during the early 1950s. Over the course of his career Mr. Trienens would argue eight cases before the U.S. Supreme Court.

Colleagues said Mr. Trienens had an extraordinary memory for dates and details and the ability to quickly understand legal issues and calmly communicate remedies to problems to judges and clients.

“He could simplify a complex question. It was like having an easy golf swing,” said Thomas Cole, senior counsel at Sidley.

As his legal work wound down, Mr. Trienens became increasingly involved in the administration of his alma mater, Northwestern University. He served as chairman of the board of trustees for nearly a decade ending in 1995. During that time, he shepherded the strengthening of the university’s finances, the expansion of its endowment and upgrades to its sports programs and athletic facilities.

Mr. Trienens was preceded in death by his wife Paula and a son. He is survived by a son, daughter and several grandchildren.

Write to Bob Tita at robert.tita@wsj.com