House Democrats have balked at the immunity, refusing to include it in a bill they drew up and saying they would not even consider it unless the administration produced long-sought documents on the origins of the program.

Mr. Rockefeller received little in the way of contributions from AT&T or Verizon executives before this year, reporting $4,050 from 2002 through 2006. From last March to June, he collected a total of $42,850 from executives at the two companies. The increase was first reported by the online journal Wired, using data compiled by the Web site OpenSecrets.org.

Neither Mr. Rockefeller’s predecessor as committee chairman or his House counterpart received increases in contributions from the phone companies, records show. But industry executives have given significant contributions to a number of other Washington politicians, including two presidential contenders, Senators Hillary Rodham Clinton and John McCain.

A spokeswoman for AT&T, Claudia B. Jones, said contributions from its executives related to Mr. Rockefeller’s role on the Senate Commerce Committee, not immunity or other questions before the Intelligence Committee.

“Many AT&T executives work with the leaders of both the House and Senate Commerce Committees on a daily basis and have come to know them over the years,” Ms. Jones said.

She added that although industry executives and politicians might not always agree, it is “commonplace for AT&T employees to regularly and voluntarily participate in the political process with their own funds.”

Ms. Morigi, in Mr. Rockefeller’s office, said the senator had had numerous meetings with his aides about immunity for a year and came to believe that the carriers needed legal protection to ensure cooperation on national security operations.