In a blow to broadcasters, the Federal Communications Commission voted 4-1 Thursday to reject a National Association of Broadcasters proposal that would have required cable operators to carry all of the programming streams broadcast on digital. Under the agency’s ruling, cable operators will be required to carry only one of the DTV programming streams offered by a broadcaster — the main one — no matter how many streams that broadcaster offers.

Under the FCC’s ruling, the digital carriage obligation goes into effect only after a broadcaster switches to digital. Broadcasters have long argued that cable carriage of all DTV programming streams multicast would be critical to the success of the broadcast digital transition. But a majority of the FCC’s commissioners — with Republican Kevin Martin the sole dissenter — appeared more sympathetic to the cable TV industry’s argument that a multicast carriage requirement would raise First Amendment concerns.

The one major surprise at the FCC’s meeting was Democratic Commissioner Jonathan Adelstein’s vehement public statement that he had voted cable’s way largely because broadcasters refused to swap beefed-up public-interest obligations in exchange for multicast carriage. “When I call on the industry to do more and they don’t, there are consequences, and I think one of those consequences we’re seeing here today,” Mr. Adelstein said.

Michael Powell, the FCC’s Republican chairman, publicly distanced himself from the “air of punitiveness” in Mr. Adelstein’s remarks, describing the retaliation implied by his Democratic colleague as “dangerous.” Instead, Mr. Powell said the agency’s decision interpreted an “ambiguous” congressional statute. “Nothing more and nothing less,” Mr. Powell said.

In a statement, Robert Sachs, president and CEO of the National Cable & Telecommunications Association, called the decision a “major victory for consumers because it ensures that the marketplace, not government, will determine which programs local cable systems carry.”

The NAB said it will continue to fight. “NAB will be working to overturn today’s anti-consumer FCC decision both in the courts and in Congress,” said Eddie Fritts, NAB president and CEO.