WASHINGTON (Reuters) - The U.S. Supreme Court said on Wednesday it would hear an Obama administration appeal defending part of the Patriot Act, which has been criticized by civil liberties groups for giving the government broad powers.

U.S. Supreme Court Associate Justice Sonia Sotomayor (L) walks out of the Supreme Court building with Chief Justice of the United States John Roberts after her investiture ceremony in Washington September 8, 2009. REUTERS/Molly Riley

The justices agreed to review a U.S. appeals court ruling that struck down as unconstitutionally vague a law that makes it a crime to provide support to a foreign terrorist group.

The law, first adopted in 1996, was strengthened by the USA Patriot Act supported by then-President George W. Bush and approved by Congress right after the September 11 attacks in 2001. It was amended again in 2004.

The high court is expected to hear arguments in the case early next year, with a decision likely by June. It will be the first time the court will consider part of the Patriot Act.

Convictions under the law, which bars knowingly providing any service, training, expert advice or assistance to a designated foreign terrorist group, can result in sentences of 15 years to life in prison.

The law does not require any proof that the defendant intended to further any act of terrorism or violence by the foreign group.

“The material support law resurrects guilt by association and makes it a crime for a human rights group in the United States to provide human rights training,” said David Cole, a Georgetown University law professor and the lead attorney challenging the law.

“We don’t make the country safer by criminalizing those who advocate nonviolent means for resolving disputes. Congress can and should draw a clear line between assistance that further terrorism and that which does not,” Cole said.

The Obama administration appealed to the Supreme Court and called the law “a vital part of the nation’s efforts to fight international terrorism.”

Since 2001, the United States has charged about 120 defendants with the material support of terrorism and about half have been convicted, the Justice Department said.

“Many of those prosecutions potentially prevented substantial harm to the nation,” Solicitor General Elena Kagan said in the appeal. Defendants have been charged under the law with “providing al Qaeda with martial arts training and instruction” and “medical support to wounded jihadists.”

The challenge had been brought by groups and individuals who want to provide support to the Kurdistan Workers Party in Turkey and the Liberation Tigers of Tamil Eelam in Sri Lanka. The State Department designated both as foreign terrorist groups.

The Humanitarian Law Project, a human rights group in Los Angeles, previously provided human rights advocacy training to the Kurdistan Workers Party, known as the PKK, and the main Kurdish political party in Turkey.

The Humanitarian Law group and others sued in 1998 in an effort to renew support for what they described as lawful, nonviolent activities overseas.