WASHINGTON—Big phone and cable companies are outgunning Silicon Valley in last-minute lobbying to shape a pending Federal Communications Commission proposal to prevent Internet providers from interfering with web traffic.

The major broadband companies have opposed FCC Chairman Julius Genachowski's efforts to give the government a stronger hand in regulating how web traffic is managed, and have warned that the FCC could discourage investment in broadband networks. But they're now trying to make sure the rules that are enacted are as positive for their businesses as possible.

In the past two weeks, executives from Verizon Communications Inc. and AT&T Inc. have reported at least nine meetings or phone calls with senior FCC staff, according to FCC records. AT&T CEO Randall Stephenson called Mr. Genachowski on Nov. 23, and Verizon CEO Ivan Seidenberg rang the next day. Verizon Wireless CEO Daniel Mead visited Mr. Genachowski on Dec. 3 to tell him that "new rules are not warranted" but if enacted should come with a provision that they expire at some point.

Silicon Valley's lobbying effort has been more muted. An Amazon.com lawyer called several legal advisers to FCC commissioners in late November. Skype Ltd. lawyers met with the agency's general counsel, and the Open Internet Coalition, which represents companies including Google Inc., Facebook Inc., eBay Inc, and Twitter Inc., had three meetings or calls with senior FCC staff. Just one CEO called, Dish Network 's Charlie Ergen, who spoke to Mr. Genachowski on Nov. 23.