"It is with great sadness that I have to report that my wife and best friend, Karen Black has just passed away, only a few minutes ago. Thank you all for all your prayers and love, they meant so much to her as they did to me," read his post on the social networking website.
In November 2010, Black was diagnosed with ampullary cancer, a rare form of the disease which affects the bile duct, and she had one third of her pancreas removed.
She went public with her health battle in 2012. In March 2013, she launched an appeal to help fund her treatment on crowdsourcing website kickstarter.com.
Black appeared in over 100 movies, but she is best known for her role as Rayette Dipesto in 1970 movie 'Five Easy Pieces', for which she even earned a best supporting actress Academy Award nomination.
During a career spanning five decades, Black also starred in movies including 'The Great Gatsby' (1974), for which she also won a Golden Globe award, 'The Day of the Locust' and 'Nashville'.
She was married three times before she exchanged vows with Eckelberry in 1987.