John Howard Fetting Jr., former president of a well-known downtown and Towson jewelry business, died Sunday of a stroke at his North Baltimore home. He was 79.

The former president of A.H. Fetting Co., where he was an officer for 45 years, he also headed two merchants' groups, the Charles Street Association and the Towson Plaza Association.

Born in Baltimore, he was raised on 33rd Street in Waverly. He attended St. Bernard parochial school before graduating from Loyola High School in 1941, where he played varsity baseball and ice hockey.

"He was an accomplished and natural athlete," said James J. Lacy, his brother-in-law and a former Loyola College basketball top scorer. "Jack was a classy first baseman and an outstanding ice hockey player."

While at Holy Cross College in Worcester, Mass., he enlisted in the Marine Corps. After additional government-sponsored schooling at Villanova University, he became a lieutenant and was assigned to Hiroshima to help rebuild that Japanese city after the atomic bomb had been dropped. He completed his degree requirements at Loyola College in 1949, where he also played baseball.

In 1947, Mr. Fetting started as a salesman in the jewelry business founded here by his ancestors in 1873. A 1991 Evening Sun profile said of him, "As always, he was dressed in a conservative gray suit, looking more the part of an investment banker than a jeweler." In fact, Mr. Fetting had served a three-year term as a board member of the Baltimore branch of the Federal Reserve of Richmond in the 1960s.

"He was an important presence on Charles Street," said Walter Sondheim of the Greater Baltimore Committee. "He tried long and hard to sustain the quality of his business. He had high, high standards."

Family members said that in 1954, Mr. Fetting was interviewed by Walter Hoving, the chairman of Tiffany & Co. who later headed the Metropolitan Museum of Art, to become the Baltimore sales agency for Hoving's New York jewelry and gift store.

"When he returned home that day, he wasn't sure if he had passed the test," said his son, Mark R. Fetting of Lutherville. "But he did."

Mr. Fetting, who once said his customers "were discriminating and demanding," directed decorators to make sure his show windows possessed a sense of drama to create a simple, direct effect. The windows often featured Edward Boehm porcelain birds, diamonds and Rolex watches, as well as Tiffany gold and silver pieces.

In 1959, Mr. Fetting opened a second store in the Towson Plaza Shopping Center, and a decade later it was outselling the downtown Charles Street store. In 1979, he closed the downtown shop but kept his office and jeweler's workroom there.

"I have my own affection for downtown," he said. "The closing was a proper business decision, but it doesn't eliminate the emotional aspects of all this."

Colleagues recalled Mr. Fetting as a natural leader and congenial competitor. He led a group of Charles Street merchants each morning at an informal coffee hour at the old John Minor lunchroom. For more than four decades he belonged to the Charles Street Association, and in 1968, he was elected its president. Many of his friends called him Jack, but he got the nickname "Diamond" when he played squash at the Maryland Club, where he won championships.

In 1991, Mr. Fetting retired and closed his business. He mailed each customer an announcement. And as a way of wishing those final customers goodbye, his last show window featured a man tipping his hat to an audience from a stage. Behind him was a sign with a single word: "Farewell."

A Mass of Christian burial will be offered at 10 a.m. today at St. Ignatius Roman Catholic Church, Calvert and Madison streets.

Survivors also include his wife of 52 years, the former Mary Angela Lacy; another son, Dr. John H. Fetting III of Baltimore; three daughters, Dr. Margaret A. Fetting of Camarillo, Calif., M. Lacy Kotansky of New Freedom, Pa., and R. Jean Fetting of Little Rock, Ark.; and 12 grandchildren.