WASHINGTON — The Senate Judiciary Committee punted yesterday over whether to shield telecommunications companies from civil lawsuits for allegedly helping the government eavesdrop on Americans.

That decision — the main sticking point in a rewrite of the Foreign Intelligence Surveillance Act — will be left to the full Senate. The FISA law dictates when the government must obtain court permission to conduct electronic eavesdropping, and President Bush has promised to veto any rewrite that does not provide legal immunity to telecom companies. About 40 civil lawsuits have been filed against telecom companies alleging they broke wiretapping and privacy laws.

The Senate panel rejected, 11–8, an attempt to strip the immunity provision out of the bill.

The committee’s chairman, Senator Leahy, a Democrat of Vermont, said granting immunity would give the Bush administration a “blank check” to do what it wants without regard to the law. Senator Specter of Pennsylvania, the panel’s top Republican, also is leery of full immunity.

He says court cases may be the only way Congress can learn exactly how far outside the law the administration has gone in eavesdropping in America.

When the full Senate takes up the bill, Mr. Specter is likely to offer a compromise that would shield the companies from financial ruin but allow lawsuits to go forward by having the federal government stand in for the companies at trial.