(Adds details in paragraphs 4-6)
WASHINGTON, Oct 9 (Reuters) - The U.S. Supreme Court on Tuesday refused to consider a challenge to a 2008 federal law granting immunity to AT&T Inc and other telecommunications companies for helping the government eavesdrop on customers' private phone conversations.
Section 802 of the Foreign Intelligence Surveillance Act, passed in the wake of the attacks of Sept. 11, 2001, bars a variety of civil actions against anyone providing assistance to the intelligence community.
Last December, the 9th U.S. Circuit Court of Appeals in San Francisco let customers pursue lawsuits accusing the government of using a "dragnet" against ordinary citizens, but it rejected arguments in 33 lawsuits against phone companies such as AT&T, Sprint Nextel Corp and Verizon Communications Inc .
The Electronic Frontier Foundation, the American Civil Liberties Union and others argued in an appeal to the Supreme Court on behalf of customers that Section 802 violated the separation of powers doctrine of the U.S. Constitution.
They said the law allowed the executive branch to conduct "warrantless, suspicionless domestic surveillance" without fear of review by courts, and gave the Attorney General sole discretion to decide when eavesdropping was necessary.
The Obama Administration argued that lawsuits against phone companies should be dismissed to encourage cooperation in efforts to fight terrorism and help ensure that state secrets be kept under wraps.
Without comment, the high court refused to review the groups' challenge to the law.
The case is Hepting et al v. AT&T Corp et al, U.S. Supreme Court, No. 11-1200.
(Reporting by Terry Baynes and Jonathan Stempel; editing by Claudia Parsons)
((firstname.lastname@example.org)(+1 646 223 6317)(Reuters Messaging: email@example.com)(terry.baynes@thomson euters.com)(+1 646 223 8022)(Reuters Messaging: firstname.lastname@example.org))
Keywords: USA COURT/TELECOM