Hagel, in a separate letter to committee Republicans, had tried to explain that some of the information they were seeking was not available.
"My role with respect to the entities you identify is as a current and former board or advisory board member. I was not involved in the day-to-day management of any of these firms, and have not been involved with some for the firms for years now," Hagel wrote. "Thus, as a matter of fact, I do not believe I have any of the information requested. More importantly, the information you seek is legally controlled by the individual entities and not mine to disclose."
Senate Democrats, who hold the majority, continue to stand behind the nomination, and no Democrat has said he or she would vote against the president's pick for his second-term national security team. Hagel, 66, is a decorated Vietnam combat veteran.
About a dozen Republicans have said they would oppose their former colleague and several others have indicated they were likely to vote no.
Democrats hold a 55-45 advantage in the Senate, and two Republicans have announced their support for Hagel — Sens. Thad Cochran of Mississippi and Mike Johanns of Hagel's home state of Nebraska. More than a handful of Republicans, including Sen. John McCain, R-Ariz., have said they oppose a filibuster of the nomination.
Last month, Hagel told Pentagon officials he would divest some of his financial holdings and resign from several corporate boards and public interest groups to avoid potential conflicts of interest if he wins Senate confirmation.
He said he would resign his corporate board post at Chevron Corp. and shed investments in the energy company, a major government contractor. He also would cut ties and investments with the McCarthy Group LLC, an Omaha-based private equity firm.
Hagel also pledged to cut ties with several academic and public interest groups, including Georgetown University and the Atlantic Council.