(Adds details, paragraphs 3-7)
By Lawrence Hurley
WASHINGTON, April 22 (Reuters) - U.S. Supreme Court justices appeared unsure on Tuesday whether to rule against online TV startup Aereo Inc in a major copyright case, with several raising concerns about how a ruling in favor of broadcast networks could affect increasingly popular cloud computing services.
Aereo, backed by media mogul Barry Diller, could be forced to shut down if the high court rules for the four major television broadcasters, who say the service violates copyright law.
Aereo, backed by Diller's IAC/InterActiveCorp, charges users a low monthly fee to watch live or recorded broadcast TV channels on computers or mobile devices. Aereo, which launched in 2012, does not pay the broadcasters.
The nine justices gave little sign of support for Aereo during the one-hour oral argument, but the bigger concern appeared to be the possible broader implications of a ruling against the company.
Several justices appeared troubled about a ruling that would deal a blow to increasingly popular cloud computing services in which personal files - including TV shows and music - are stored remotely on the Internet on servers from companies such as Google Inc, Microsoft Corp, DropBox Inc and Box Inc.
Justice Stephen Breyer told the networks' attorney, Paul Clement, that his legal argument "makes me nervous about taking your preferred route."
The company's fate was placed in the hands of the high court when Walt Disney Co's ABC network, CBS Broadcasting Inc, Comcast Corp's NBCUniversal and Twenty-First Century Fox Inc appealed a decision by the 2nd U.S. Circuit Court of Appeals in April 2013 that denied their request to shut Aereo down while litigation moved forward.
(Reporting by Lawrence Hurley; Editing by Will Dunham)
Our Standards: The Thomson Reuters Trust Principles.