"The contemplated action by the FCC is perplexing in that only last year, the same commission approved the largest telecommunications deal in history with the [AT&T, BellSouth] merger, as well as two other Bell company mega-mergers in the past three years," David Cohen, executive vice president at Comcast, said in a statement.

"Against the backdrop of these decisions that have strengthened the hands of our Bell competitors, it is unthinkable that the government would constrain the ability of cable companies like Comcast to compete."

In 2001, the U.S. Circuit Court of Appeals for the District of Columbia overturned the 30 percent threshold after deciding there was not enough evidence to justify it. Kyle McSlarrow, president and chief executive officer of National Cable and Telecommunications Association, told reporters this spring that if the cap returns, it would face new legal challenges.

Nevertheless, the system operators and programmers that comprise NCTA's membership are divided. While the re-regulation threatened by Martin would have had industry-wide repercussions, the cap would mostly affect major operators.

After Comcast, Time Warner is the second-largest cable provider, but it only commands 14 percent of the pay-TV market, putting it well below a new limit. Some programmers even consider the restriction advantageous because it would prevent operators they negotiate with from becoming too dominant, a source said.

Another reason for NCTA's measured response is that a cap only halts the growth of video subscribers through mergers and acquisitions. Even at 27 percent, Comcast could add 3 million video customers by purchasing small systems before hitting the benchmark.

Also, the proposal would not bar Comcast or other operators from surpassing the 30-percent level by attracting new customers to existing services, nor would it prevent cable systems from acquiring non-video companies, such as cellular providers. The association has not considered the cap to be among its top policy priorities, an industry source said.

The cable industry expended considerable political capital fighting Martin's attempt this week to declare that cable systems have reached a level of market dominance, a finding that triggers fresh regulations under a 1984 law. An extensive lobbying campaign prompted several letters to the FCC from prominent lawmakers and minority groups expressing opposition.

On Tuesday, after nearly 12 hours of delay to accommodate last-minute negotiations, the FCC approved a watered-down proposal to collect more subscriber data to better gauge cable's reach.