U.S. security chiefs testify before Senate Intelligence Committee hearing on "worldwide threats" on Capitol Hill in Washington Thomson Reuters By Jonathan Landay and Mark Hosenball

WASHINGTON (Reuters) - Republicans are resisting requests by Democrats for U.S. intelligence chiefs to present their annual global threat report to a congressional panel so they can avert a likely showdown with the head of the FBI over aspects of the Trump-Russia investigation, two Democratic sources said on Wednesday.

Republican leaders on the U.S. House of Representatives Intelligence Committee have not scheduled the customary hearing, said the Democratic sources, who spoke on condition of anonymity.

On Tuesday, FBI Director Christopher Wray joined Director of National Intelligence Dan Coats, CIA Director Mike Pompeo and other agency heads when they presented the 2018 Worldwide Threat Assessment report to the Senate Intelligence Committee.

If the House committee were to bring in intelligence chiefs, Democrats would almost certainly ask Wray about "material omissions of fact" the FBI found in a classified memo Republicans on the panel released this month.

The memo asserted FBI and Justice Department bias against President Donald Trump in seeking a 2016 warrant to monitor the communications of Carter Page, a former Trump campaign adviser.

A U.S. official, also speaking on condition of anonymity, confirmed that none of the directors of the leading U.S. intelligence agencies has been invited.

Jack Langer, a spokesman for the committee chairman, Representative Devin Nunes, a Republican who is a staunch Trump supporter, declined to comment.

The dispute is the latest sign of partisan fighting over several investigations arising out of U.S. intelligence agency conclusions that Russia directed a hacking campaign and spread disinformation to meddle in the 2016 election.

Trump has dismissed three congressional investigations and one by U.S. Special Counsel Robert Mueller as a "witch hunt." Russian President Vladimir Putin has denied Moscow sought to interfere in the election and Trump has said he believes him.

Trump denies any collusion between his campaign team and Russian officials.

At Tuesday's Senate panel hearing, intelligence chiefs said Russia was likely to try to attack the 2018 U.S. midterm elections in November.

Mike Quigley, a committee Democrat, said that skipping the hearing would deprive lawmakers of the ability to question the intelligence chiefs in public about their assessments.

"We are flying blind for political reasons," Quigley said.

(Reporting by Jonathan Landay and Mark Hosenball; additional reporting by Patricia Zengerle; Editing by John Walcott and Grant McCool)