"This Is It", the documentary movie that followed Michael Jackson's concert rehearsals in the days before his shock death in June, earned $20.1 million at the US box office on its first full day of release, according to The Hollywood Reporter Thursday.

The film earned a $12.7 million internationally and another $7.4 million in the US, the report said.

The enthusiastic reception could prompt Sony Pictures to extend the movie's two week screening window, as positive reviews and word-of-mouth approval send more fans to see the 90-minute documentary culled from some 100 hours of rehearsal footage.

The box office haul was released in conjunction with a report from Forbes magazine that identified Jackson as one of the year's top earning dead celebrities. He earned $90 million in the year, including $72 million since his death.

Jackson was beaten by fashion designer Yves Saint Laurent, who earned $350 million, and songwriting duo Richard Rodgers and Oscar Hammerstein who earned $235 million. But he came ahead of last year's No. 1, Elvis Presley, with $55 million; "The Lord of the Rings" author J.R.R. Tolkien with $50 million; and John Lennon with $9 million.