HANOI (Reuters) - Vietnam said on Thursday that normal legal procedures must apply in the case of a Catholic priest found guilty of spreading anti-government propaganda, after U.S. senators called for his release.

The U.S. senators urged Vietnam's president on July 1 to immediately and unconditionally free Father Thadeus Nguyen Van Ly, and human rights groups said his imprisonment justified putting Hanoi on a U.S. religious freedom blacklist.

"Consideration on releasing Nguyen Van Ly will be given in line with Vietnamese law," Foreign Ministry spokesman Le Dung told a regular briefing in Hanoi.

He said Ly was arrested, tried and sentenced for violations of the law, "not for any religious reasons or his political view".

Vietnam often grants amnesties to selected prisoners for good behaviour ahead of major national holidays such as the April 30 Liberation Day, the National Day on Sept. 30 and the Lunar New Year festival in January or February.

The 37 senators, led by Democrat Barbara Boxer and Republican Sam Brownback, had urged President Nguyen Minh Triet to free the 63-year-old cleric, calling his trial "seriously flawed".

But Dung denied the accusation, saying: "The trial of Nguyen Van Ly was public and his rights at the court were protected in accordance with Vietnamese law."

He was jailed for eight years in March 2007.

In May Vietnam acknowledged some human rights "wrongdoings" in an appearance before a U.N. watchdog but rejected exiles' allegations about the mistreatment of dissidents and minorities.