CAIRO, Dec 12 (Reuters) - An Egyptian Copt arrested on suspicion of posting online an anti-Islam film that ignited Muslim protests around the world was sentenced on Wednesday to three years in prison, a court source said

Computer science graduate Alber Saber, 27, was arrested at his Cairo home on Sept. 13 after neighbours accused him of uploading sections of the film "Innocence of Muslims" and making another movie mocking all religions.

Saber can appeal the ruling issued by a Cairo court after paying bail of 1,000 Egyptian pounds ($160).

The case has raised concerns over freedom of expression under Islamist President Mohamed Mursi, who came to power in free elections earlier this year after the popular uprising in 2011 that toppled autocrat Hosni Mubarak.

Human right groups including Amnesty International have called for Saber's release.

Prosecutors accused Saber of running Facebook pages calling for atheism, insulting Islam and Christianity and questioning religious beliefs.

The anti-Islam film, made in California, portrayed the Prophet Mohammad as a womaniser, thug and child molester. Crowds stormed U.S. embassies around the Arab world in protest at it. In Libya, the U.S. ambassador was killed by Islamist militants.

Many Christian Copts have been concerned about the political rise of Islamists since Mubarak's fall and fret about any action that could stoke tensions with their Muslim compatriots. ($1 = 6.1510 Egyptian pounds) (Reporting By Tamim Elyan; Editing by Giles Elgood)