WASHINGTON (Reuters) - U.S. Special Counsel Robert Mueller has subpoenaed the Trump Organization for documents, including some related to Russia, the New York Times reported on Thursday, citing two people briefed on the matter.

Details of the subpoena were not available, the newspaper said. The Trump Organization, which U.S. President Donald Trump ran with his family before he entered the White House, played down the significance of any subpoena, a lawyer saying on Thursday that the company has told the public since July that it is being cooperative with the special counsel's investigation.

Mueller is investigating Russian attempts to influence the 2016 U.S. election, and potential collusion by Trump aides. Russia has denied U.S. intelligence agencies' conclusion that it meddled in the election and Trump has said there was no collusion between his campaign and Moscow officials.

Mueller has charged several Trump associates and more than a dozen Russians.

Peter Carr, a spokesman for Mueller, declined to comment on the Times report about a subpoena, which was the first known time Mueller had demanded materials directly related to Trump’s businesses.

The S&P 500 ended slightly lower on Thursday in choppy trade as strong jobs and manufacturing data was balanced by the Times report on Mueller's subpoena.

"This is old news and our assistance and cooperation with the various investigations remains the same today," New York lawyer Alan Futerfas, who represents the Trump Organization in the Russia probe, said in a statement.

Futerfas also represents Donald Trump Jr. and other Trump Organization officers and employees.

Congressional committees also have been investigating Russia and the 2016 election and possible collusion with the Trump campaign.

The White House declined to comment specifically on the report and referred questions to the Trump Organization.

"We're going to continue to fully cooperate. Out of respect for the special counsel, we're not going to comment," White House spokeswoman Sarah Sanders said.

(Reporting by Karen Freifeld, Doina Chiacu and James Oliphant; editing by Grant McCool)