(Corrects first name to Sylvia from Sheila in paragraph 8)
By Mark Felsenthal
WASHINGTON, Feb 12 (Reuters) - In an unusual move, the White House will release some budget data the week after it publishes its principal budget document, an administration official said on Wednesday.
The White House will release the main budget volume, which contains all of President Barack Obama's key proposals and government agency-level information on March 4 as scheduled, a White House official said. The administration will also release the appendix that includes background information that is considered useful to lawmakers who will ultimately pass legislation detailing how the government will spend its money, the official said.
However, historical tables and a volume containing supplemental analyses of budget data will be released the following week, the official said, citing the short span of time between the passage of a spending bill in January and the budget rollout seven weeks later.
"All relevant information for the Congress and the public to understand and evaluate the President's Budget will be released on March 4," the White House official said.
The materials to be released the following week "provide highly technical background and historical information, the vast majority of which is already publicly available," the official added.
The president's budget proposal is for fiscal year 2015, which begins Oct. 1.
Analysts said the two-stage release is unusual but that it should not prevent lawmakers from analyzing the presidents' proposals since all of his requests for future spending are in the main budget document.
However, a spokesman for Senator Jeff Sessions, the top Republican on the Senate Budget committee, said that committee Republicans expect to have the entire budget prior to the testimony of the White House Office of Management and Budget, Sylvia Mathews Burwell. Burwell is due to testify in the days after the budget release.
Obama and congressional Republicans have fought bitterly over spending and taxes since 2011, resulting in a near default and a government shutdown in October.
The president's annual budget proposal is primarily a wish list that has no binding effect on congressional appropriators. Still, Obama's requests will provide a starting point for his fellow Democrats, who control the Senate but are in the minority in the House of Representatives.
But the president's budget proposal will be of even less significance this year than it has been in past years because lawmakers agreed in January not only to an overall spending cap for 2014 but for the following year as well.
Even so, the request will be a roadmap for some of the policy initiatives Obama plans to throw his weight behind in coming months. (Editing by Ken Wills and Eric Walsh)