WASHINGTON--A U.S. Senate panel narrowly rejected strict Net neutrality rules on Wednesday, dealing a grave setback to companies like eBay, Google and Amazon.com that had made enacting them a top political priority this year.

By an 11-11 tie, the Senate Commerce Committee failed to approve a Democrat-backed amendment that would have ensured all Internet traffic is treated the same no matter what its "source" or "destination" might be. A majority was needed for the amendment to succeed.

Republican committee members attacked the idea of inserting Net neutrality regulations in a massive telecommunications bill, echoing comments from broadband providers like AT&T and Verizon, which warned the rules were premature and unnecessary.

Democrats had rallied behind an amendment, adapted from a standalone bill they offered in May, which would have barred network operators from discriminating "in the carriage and treatment of Internet traffic based on the source, destination or ownership of such traffic."