By Patricia Zengerle and Joseph Menn

WASHINGTON, Oct 31 (Reuters) - The U.S. Senate Intelligence Committee approved legislation on Thursday that would tighten controls on the government's sweeping electronic eavesdropping programs but allow them to continue.

In a classified hearing, the panel voted 11-4 for a measure that puts new limits on what intelligence agencies can do with bulk communications records and imposes a five-year limit on how long they can be retained.

Despite growing national concern about surveillance, the "FISA Improvements Act" would not eliminate programs that became public this year after former National Security Agency contractor Edward Snowden leaked documents describing how the government collects far more internet and telephone data than previously known.

"The NSA call-records program is legal and subject to extensive congressional and judicial oversight, and I believe it contributes to our national security. But more can and should be done to increase transparency and build public support for privacy protections in place," Senator Dianne Feinstein, chairwoman of the committee, said in a statement.

If approved by the full Senate and the House and signed by the president, the act would require the special court that oversees the collection programs to designate outside officials to provide independent perspective and assist in reviewing matters that present novel or significant interpretations of the law.

It also requires Senate confirmation of the NSA director and inspector general.

However, the bill ran into immediate opposition from technology companies, civil-liberties groups and another chairman in the majority Democratic Senate.

Democratic Senator Patrick Leahy and Republican Representative James Sensenbrenner this week introduced a bill to end what they termed the government's "dragnet collection" of information.

Sensenbrenner and Leahy, the chairman of the Senate Judiciary Committee which also oversees the Foreign Intelligence Surveillance Act, were the primary authors of the USA Patriot Act implemented after the Sept. 11, 2001, which gave law enforcement and intelligence agencies much more authority.

CODIFY SURVEILLANCE PRACTICES

Democratic Senator Ron Wyden, one of the four intelligence committee members voting against their panel's legislation, said it would codify surveillance practices that are too broad.

"More and more Americans are saying that they refuse to give up their constitutionally guaranteed liberties for the appearance of security; the intelligence committee has passed a bill that ignores this message," Wyden said in a statement.