Oscar-nominated actor and “Green Acres” star Eddie Albert died Thursday of pneumonia in Pacific Palisades, Calif. He was 99.

The affable thesp was nominated for supporting actor Oscars for “Roman Holiday” in 1953 and “The Heartbreak Kid” in 1972. A leading environmental activist, he was also one of the first actors to ever appear on television, in an experimental 1936 transmission.

Albert appeared in dozens of films including “Oklahoma!,” “Teahouse of the August Moon,” “The Sun Also Rises” and “The Longest Yard.” But his most indelible role was that of Oliver Wendell Douglas, the lawyer-turned-gentleman farmer who served as the straight man to his ditsy wife Lisa, played by Eva Gabor, and a motley array of comic rural characters, including Arnold the pig, on “Green Acres.” The sitcom ran on CBS from 1965-71.

He also co-starred with Robert Wagner in the series “Switch” from 1975-78 and was a semi-regular on “Falcon Crest” in 1988.

Born Edward Albert Heimberger in Rock Island, Ill. to German immigrants, Albert worked as a theater usher, trapeze artist in a Mexican circus and radio announcer before beginning what would be a 75-year career in Hollywood.

His first movie role was in 1938’s “Brother Rat,” co-starring with another unknown, Ronald Reagan. His role in the 1956 antiwar film “Attack,” in which he portrayed a deranged military officer, was especially meaningful to him. During his WWII service in the Navy in the bloody battle of Tarawa, he rescued scores of wounded Marines under heavy fire and was awarded the Bronze Star.

Protecting the environment was a priority for Albert before it became fashionable in Hollywood: He initiated and headed the successful campaign to outlaw the toxic pesticide DDT, attended the dinner where the word “ecology” was coined and was a longtime advocate of organic foods and physical fitness. Earth Day is celebrated on his birthday, April 22.

While he continued to act after WWII, Albert’s career took many unexpected turns. In the early 1950s, he headed the department of communication and education for Henry J. Kaiser Industries, and he is credited with helping to establish the first coaxial cable, connecting the Hawaiian Islands with the mainland for the first time. While on location with director John Huston in Africa, he worked with the United Nations to bring food to 5 million African children, which became the Meals on Millions program. In 1946, he produced controversial sex ed films “Human Beginnings” and “Human Growth” for schoolchildren.

In 1945 he married Mexican actress Margo, who had appeared in “Lost Horizon.” She established Plaza de la Raza, a Los Angeles arts foundation for disadvantaged Latino children and died in 1985. They had two children.

Albert’s last TV appearance was on the show “War Stories,” with Oliver North. His more than 100 guest appearances on TV included stints on “The Man From U.N.C.L.E.,” ‘Kung Fu,” “Simon and Simon,” “The Love Boat,” “thirtysomething” and “General Hospital.”

He is survived by his son, Edward, an actor; daughter Maris; and two granddaughters.

Donations may be made to Plaza de la Raza at Plazadelaraza.org.

— Pat Saperstein