The American film and television world reacted with sadness on Sunday to news of the death of the Emmy winning actor James Garner, who died in Los Angeles at the age of 86.

The Star Trek star William Shatner said: “Sending thoughts and prayers to the family of James Garner this morning.”

Garner, who had open-heart surgery in 1988 and suffered a stroke in 2008, was reported to have died of natural causes.

Born in Norman, Oklahoma, on 7 April 1928, he began his acting career in the 1950s, after serving in the Korean war, in which he was wounded twice. He was best known for his roles as a wise-cracking Wild West card sharp, in Maverick, and an ex-con turned private eye in The Rockford Files.

Primarily known as a star of the small screen – he made a number of Rockford Files TV movies, despite leaving the regular series in 1980 – Garner gained one Oscar nomination, for the 1985 romantic comedy Murphy's Romance, in which he played a small-town druggist opposite Sally Field. He also had supporting roles in The Great Escape – as a military “scrounger”, reportedly based on his own experiences in uniform – Support Your Local Sheriff! and the 1994 big-screen version of Maverick, with Mel Gibson.

In 2004 he had a late-career hit in Nick Cassavetes's The Notebook, in which he played the husband of a character, played by Gena Rowlands, suffering from Alzheimer's disease.

On Sunday, many actors and directors used Twitter to pay tribute. The director Ron Howard said Garner was “admired by all who knew him” and added: “When starring in [1966 motor racing film] Grand Prix the people around F1 said he had the talent to be a pro driver.”

From Britain, the Sherlock writer and star Mark Gatiss said: “Goodbye, Jim Rockford. The wonderful, amiable James Garner has gone.”

Stephen Fry said: “So sad to hear that James Garner has gone. A real part of my childhood, Rockford and the Maverick especially.”

Back in the US, the actor Bruce Campbell said “Tip of the hat to James Garner. Charm, humour, but most of all – class”, while the Sixth Sense star Haley Joel Osment saluted “the just dearly departed Legend James Garner” and added: “Rest in Peace.”

Marlee Matlin, who is deaf and who acted with Garner in a 1997 TV movie, Dead Silence, wrote: “Sad to read my dear friend and costar James Garner passed. RIP sweet Jim Rockford.”

The actor and writer Molly Ringwald tweeted: “I think James Garner was my first crush.”

Tributes also came from outside the film world.The CNN news anchor Jake Tapper noted Garner's support for the civil rights movement of the 1960s, saying “RIP James Garner” and tweeting a photo of the actor with Paul Newman, Marlon Brando and James Baldwin at the March on Washington for Jobs and Freedom on 28 August 1963.

NBC's Chuck Todd said: “Loved James Garner in just about every role, even as the lovable rogue ex-prez in My Fellow Americans. Character loosely based on Clinton?”

On Sunday, the Los Angeles Times cited the late director Robert Altman, who said in 1979: “I have long thought Jim Garner was one of the best actors around. He is often overlooked because he makes it so easy, and that is not easy to do. I don't know anyone in the business with his charm and charisma who can act so well.”

The newspaper also quoted Clint Eastwood, with whom Garner starred in Space Cowboys in 2000 and who followed Garner from the small screen. Eastwood said Garner “opened the door for people like Steve McQueen and myself”.