WASHINGTON (Reuters) - Despite initial objections, President Bush agreed Wednesday to extend until July 26 the deadline for the panel investigating the Sept. 11, 2001 attacks to finish its work, setting the stage for release of its final report at the height of the presidential campaign.

The extension was requested by the commission, which wanted the original May 27 deadline pushed back 60 days to complete interviews and review documents related to the attacks.

"We are pleased to support their request for an extension and we urge Congress to act quickly to extend that timetable" by 60 days, White House spokesman Scott McClellan told reporters.

Some lawmakers wanted to delay release of the commission's potentially damaging final report until next January, well after the November election.

"If the commission has information that can help prevent another catastrophic terrorist attack on American soil, we need to have that information as soon as possible," McClellan said.

The White House had until now resisted granting the commission any extension, arguing it should finish its work on schedule.

But pressure has mounted on the White House to back down -- from relatives of Sept. 11 victims and the commission itself.

Panel members have complained for months that the administration has been slow to provide the documents they need.

Bush's Democratic rivals have accused his administration of stonewalling, a criticism that could resonate with some voters in an election-year.

"I'm glad to see that President Bush has finally decided to take the commission's work seriously ... I just hope this latest reversal will also bring with it more cooperation from the administration," said New Jersey Democrat Sen. Frank Lautenberg.

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Earlier this week, Bush reversed himself and agreed to establish a new panel to investigate intelligence that was used to justify the Iraq war.

The Sept. 11 commission plans this weekend to interview Bush's national security adviser, Condoleezza Rice. It has already interviewed her deputy, Stephen Hadley.

Bush may also be questioned, officials said.

The commission has completed 900 interviews and several hundred remain. It is also reviewing more than 2 million pages of documents.

"We welcome the administration's support and commitment," commission Chairman Thomas Kean and Vice Chairman Lee Hamilton said in a joint statement.

They said the panel, formally known as the National Commission on Terrorist Attacks Upon the United States, would release its public, unclassified final report not later than July 26 and wrap up the rest of its business by August 25.

Several issues remain unsettled, however.

The White House and the commission remain at odds over access to notes taken by panel members from highly classified presidential briefing papers.

A November agreement allowed four members of the commission to review documents known as the President's Daily Briefs, including one from August 2001 that warned of the possibility of an al Qaeda plot to hijack airplanes.

But the White House has balked at allowing the notes to be shared more broadly among commissioners and investigators. Commission officials say negotiations are underway and an agreement could be reached this week.