LOS ANGELES (Reuters) - Actor Ron Palillo, who played class joker Arnold Horshack in the 1970s TV comedy series "Welcome Back, Kotter," died on Tuesday at the age of 63.

Palillo's Los Angeles-based agent, Jackie Stander, said that the actor died in Palm Beach, Florida.

Celebrity news website TMZ.com reported that Palillo died of an apparent heart attack at his home near Palm Beach. The website said he was found before dawn on Tuesday by his partner and pronounced dead at a nearby hospital.

Palillo, whose character was known for the catch-phrase "Ooh-ooh-ooooh!" and his nervous "aawwk" laugh, played Horshack for four years in the 1975-79 ABC comedy, which also starred John Travolta.

The show captured the antics of an unruly group of remedial high school students and their wise-cracking teacher, Gabe Kotter, played by comedian Gabe Kaplan.

Palillo went on to play numerous supporting roles in TV series, including "Ellen," and doing voiceover work as Sgt. Squealy in the 1980s animated series "Laverne & Shirley."

In the 1990s, he went to New York and took lead roles in plays and musicals like "Amadeus," "Guys and Dolls" and "Who's Afraid of Virginia Woolf?."

Most recently, Palillo was a teacher at the G-Star performing arts and film high school in West Palm Beach.

(Reporting By Jill Serjeant; Editing by Carol Bishopric and Steve Orlofsky)