NEW YORK — Roger Enrico, the PepsiCo chief executive who nearly dethroned Coca-Cola in the 1980s, died Wednesday. He was 71.

He died suddenly while on vacation in Grand Cayman in the Cayman Islands, according to his family. The cause of death was unknown.

Mr. Enrico joined PepsiCo after serving in the Vietnam War, and he swiftly rose through the ranks. He oversaw the company’s advertising campaign during the so-called Cola Wars, making marketing deals with celebrities including Michael Jackson, Madonna, Cindy Crawford, and Michael J. Fox. And as Pepsi’s market share grew, Coca-Cola in 1985 changed its formula, then quickly changed it back after suffering the wrath of angry customers.

“We have lost one of the true legends of our company and our industry,’’ Indra K. Nooyi, the chairwoman and chief executive of PepsiCo, said in a statement Thursday.

Born Nov. 11, 1944, in Chisholm, Minn., Mr. Enrico was the son of the foreman at an iron-ore processing plant. He attended Babson College and then volunteered for the Navy, serving in Vietnam.

After returning from the war, Mr. Enrico took a job in 1971 as a brand manager for Frito-Lay, where he helped market the onion-flavored crunchy snacks called Funyuns. In 1983, at age 38, he became the chief executive of Pepsi-Cola USA and almost immediately signed a multimillion-dollar sponsorship deal with Jackson.

“He personally conducted negotiations with Michael Jackson,’’ said Allen Rosenshine, the former chief executive of BBDO, the advertising company that helped develop PepsiCo’s marketing campaign during the Cola Wars and beyond.

Rosenshine credited Mr. Enrico with creating a real distinction between Pepsi and Coke.

“He probably did more than anyone else to drive Coke to their famous formula change, which they ultimately had to withdraw,’’ Rosenshine said in an interview.

He referred to New Coke, which was supposed to be sweeter than Pepsi but was scrapped after longtime Coke drinkers protested.

“You don’t generally have a chief executive who is intimately involved with an advertising campaign,’’ he said, “but Roger was.’’

Mr. Enrico chronicled PepsiCo’s battle with Coca-Cola in his 1986 memoir, “The Other Guy Blinked — How Pepsi Won the Cola Wars,’’ written with Jesse Kornbluth. (In the end, it did not win. Coca-Cola regained market share and continues to reign supreme.)

In 1996, Mr. Enrico was named chief executive and chairman of PepsiCo. The next year, he spun off the restaurant division, composed of the Taco Bell, KFC, and Pizza Hut chains, as an independent public company, creating what is now known as Yum Brands. In 1998, he oversaw the acquisition of Tropicana and, in 2000, he struck a deal to acquire Quaker Oats, which included the Gatorade sports drink.

After his retirement from PepsiCo in 2001, Mr. Enrico served as chairman of DreamWorks Animation from 2004 to 2012.

Mr. Enrico leaves his wife, Rosemary; his son, Aaron, and three grandchildren.