NEW YORK—Jonathan Rinehart, whose Adams & Rinehart was one of the pioneers in financial and particularly M&A communications and provided the foundation on which the modern Ogilvy Public Relations was built, has died of complications from Parkinson’s Disease. He was 86.

Rinehart founded his own company, which later became Adams & Rinehart, in 1974, having previously served as head of public relations at Eastern Airlines and before that served as deputy chief of correspondents and a senior Washington correspondent for Newsweek magazine in Washington, Chicago, Los Angeles and San Francisco and Honolulu.

The firm helped shape the M&A public relations business, and Rinehart counseled a number of major US and global companies, including AT&T, Matsushita, Chevron, Consolidated Gold Fields, Seagram, American Brands, Whirlpool, Gillette, British Petroleum, Philip Morris, Phillips Petroleum, and Royal Dutch/Shell Group.

Alumni of Adams & Rinehart include George Sard, Paul Verbinnen and Joele Frank, who went on to found two of today’s most prominent corporate and financial PR specialists.

It was sold to Ogilvy & Mather Worldwide in 1986 and eventually was renamed Ogilvy Adams & Rinehart. Rinehart continued to serve as Chairman until December 31, 1994. After that, he established a New York office for Powell Tate, the Washington-based public affairs firm that is now part of Weber Shandwick. In 1998, he joined Abernathy MacGregor in an “of counsel” role.

He was also active in the non-profit realm, serving on the board of organizations including the New York Urban League, the Wildlife Conservation Society, and the National AIDS Fund.