Prince George's County Fire Chief Frank P. Briguglio, 58, who helped to patch up longstanding differences between volunteer and professional fire-fighters in the county, died yesterday in Port Charlotte, Fla.

He apparently suffered a heart attack while preparing to return home after vacationing with friends there.

Chief Briguglio, who had many years as a professional and volunteer fireman, was named acting fire chief in May 1975, and then fire chief four months later.

By then he made largely successful efforts to resolve the dispute between the two factions. He said then:

"What was needed was an opening of communication lines. Too much of the problem was the result of one faction (paid firemen) not knowing what the other faction (volunteers) were doing or talking about and vice versa.

"What I've been trying to do and will continue to try to do is to meet regularly with representatives of the groups to find out what's on everyone's mind."

Calling Chief Briguglio "both personally and professionally" a key member of his administration, County Executive Winfield M. Kelly Jr. said yesterday:

"His death is a great loss to the citizens of the county, especially to the volunteer and career members of the fire service whom he served for 43 years."

Chief Briguglio reorganized the fire department administration, putting operational and support functions under separate commands. He made a point of visiting the county's 46 fire stations to talk to firefighters on duty. He also attended many meetings of volunteer organizations to discuss administrative details.

Born in Maryland Park, he grew up in the Capitol Heights area. He served in the Navy in World War II and later worked as a fire officer in the Fort Meader Fire Department.

Before 1970, Chief Briguglio was a member of the Capitol Heights Volunter Fire Department. From 1945 to 1970, he also worked part-time as director of the county's Fire Communications Center in Hyattsville.

During that period, he also was vice president of the American Iron Works in Bladensburg.

From 1970 until he was named fire chief, he supervised the department's Bureau of Fire and Rescue Communications.

Chief Briguglio was a member and a past officer of the Mount Rainier-Brentwood Lions Club.

He is survived by his wife, Margararite, of the home in Clinton; two daughters, Patricia Alonzo, of Waldorf, and Margarite DiFabrizio, of Friendly, Md.; three brothers, Carl, of Clinton, Thomas, of Forestville, and Vincent, of District Heights; Ernestine Bellosi, of Upper Marlboro, and Thersa Green, of District Heights, nine grandchildren and one great-grandchildren.