TV sets that let viewers block objectionable programs would be available next year under a plan approved Thursday by federal regulators.

The Federal Communications Commission adopted technical standards for equipping sets with the "v-chip" blocking technology.The commission also ordered blocking technology to be included in new computers that have TV tuners. There are not many of those now, but they are expected to be much more common in the future. The TV chip would only be required to block rated TV shows viewed on computer screens. The chip would not block news, information and other content carried on the Internet.

A 1996 law requires that televisions sold in the United States with screens 13 inches and larger must eventually have the blocking technology built in.

TV set manufacturers said they needed at least 18 months to retool production lines after the FCC adopted the v-chip technical standards.

"The costs of v-chip sets will be very modest, if noticeable at all," perhaps $5 to $20, said Jonathan Thompson, spokesman for the Consumer Electronics Manufacturers Association. In high-end sets - those 27 inches and bigger - consumers probably won't see a price change, he said.

Still, manufacturers aren't bracing for a consumer stampede for v-chip sets. "Nobody has been clamoring for them," Thompson said.

The v-chip will work with detailed TV ratings that ABC, CBS, Fox and major cable networks now use and it will work with less-specific ratings that NBC now airs. Lawmakers want NBC to use the same ratings as the rest of the industry.

The FCC also approved the detailed ratings system now in use, but took no steps to prevent NBC from keeping the ratings that the rest of the industry previously used. The 1996 law requires the FCC to review the ratings.

"At this point, we want to get on with the show," said FCC Chairman Bill Kennard. But if an independent monitoring board set up by the industry were to determine that "one of the ratings systems is not working, then we might have to revisit that."

The sets would allow viewers to block all programs with an "L" for language rating, for example, but it could not be programmed to block single programs that a parent may find objectionable. However, there is technology in many TV sets and VCRs now that allow parents to block single shows.

When all programs with an "L" language rating are blocked, parents can unlock the block to watch a specific show. The sets also are expected to be able to block out programs that carry motion picture ratings, such as "PG-13," "R" and "NC-17."

TV manufacturers say sets equipped with blocking technology probably won't be in stores until next year.