Jon Landau, an Oscar-winning producer who worked closely with director James Cameron on three of the biggest blockbusters of all time, “Titanic” and two “Avatar” films, has died. He was 63.

Landau’s family announced his death Saturday. No cause of death was given.

Landau’s partnership with Cameron led to three Oscar nominations and a best picture win for 1997’s “Titanic.” Together the pair account for some of the biggest blockbusters in movie history, including “Avatar” and its sequel, “Avatar: The Way of Water.”

Cameron, in a statement, remembered “a dear friend, and my closest collaborator of 31 years.” “A part of myself has been torn away,” said Cameron.

“His zany humor, personal magnetism, great generosity of spirit and fierce will have held the center of our Avatar universe for almost two decades,” said Cameron. “His legacy is not just the films he produced, but the personal example he set – indomitable, caring, inclusive, tireless, insightful and utterly unique.”

Landau’s career began in the 1980s as a production manager, and he gradually rose through the ranks, serving as a co-producer on “Honey I Shrunk the Kids” and “Dick Tracy.”

He took on the producer role on “Titanic,” Cameron’s expensive epic about the infamous 1912 maritime disaster. The bet paid off: “Titanic” became the first movie to cross $1 billion in global box-office earnings and went on to win 11 Oscars, including best picture.

“I can’t act and I can’t compose and I can’t do visual effects, so I guess that’s why I’m producing.” Landau said while accepting the award with Cameron.

Their partnership continued, with Landau becoming a top executive at Cameron’s Lightstorm Entertainment. In 2009 the pair watched as “Avatar,” a sci-fi epic filmed and shown in theaters with groundbreaking 3D technology, surpassed the box-office success of “Titanic.” It remains the top-grossing film of all time.

Its sequel, “Avatar: The Way of Water,” is third on the list.

“Your wisdom and support shaped so many of us in ways we will always be grateful for,” Zoe Saldaña, one of the stars of the “Avatar” franchise, said in an emotional tribute on Instagram. “Your legacy will continue to inspire us and guide us in our journey.”

Landau has been a key player in the “Avatar” franchise, which saw frequent delays of the release of “The Way of Water.” Landau defended the sequel’s progress and Cameron’s ambitious plans to film multiple sequels at once to keep the franchise going.

“A lot has changed but a lot hasn’t,” Landau told The Associated Press in 2022, a few months ahead of the sequel’s release. “One of the things that has not changed is: Why do people turn to entertainment today? Just like they did when the first ‘Avatar’ was released, they do it to escape, to escape the world in which we live.”

“Jon was a visionary whose extraordinary talent and passion brought some of the most unforgettable stories to life on the big screen. His remarkable contributions to the film industry have left an indelible mark, and he will be profoundly missed. He was an iconic and successful producer yet an even better person and a true force of nature who inspired all around him,” Alan Bergman, Disney Entertainment co-chairman, said in a statement.

Landau was named an executive vice president of feature movies at 20th Century Fox when he was 29, which led him to oversee major hits including “Home Alone” and its sequel, as well as “Mrs. Doubtfire” and “True Lies,” where he first started working closely with Cameron.

Landau was also influential in bringing the manga adaptation “Alita: Battle Angel” to the big screen in 2019. Cameron supported the project, but his “Avatar” commitments kept him from directing it. Instead, Landau worked with director Robert Rodriguez to get the film completed.

Born in New York on July 23, 1960, Landau was the son of film producers Ely and Edie Landau. The family moved to Los Angeles in the 1970s, and Landau went on to graduate from the University of Southern California’s film school.

Ely Landau died in 1993. Edie Landau, the Oscar-nominated producer of films like “Long Day’s Journey Into Night,” “Hopscotch” and “The Deadly Game,” died in 2022.

Jon Landau is survived by his wife of nearly 40 years, Julie; their sons, Jamie and Jodie; and two sisters and a brother.