BOSTON (Reuters) - A Massachusetts man charged with plotting to attack the Pentagon and the U.S. Capitol with large model airplanes packed with explosives has agreed to plead guilty, authorities said on Tuesday.

Prosecutors and defense attorneys have agreed to request a 17-year sentence for Rezwan Ferdaus, 26, on charges that he attempted to damage and destroy a federal building, and attempted to provide material support to terrorists.

Ferdaus, of Ashland, Massachusetts, earlier pleaded not guilty to a total of six charges after his arrest in September 2011. In exchange for the guilty plea, the government will dismiss the remaining charges.

A U.S. citizen and a physics graduate from Northeastern University, Ferdaus was arrested after an FBI investigation during which he requested and took delivery of explosives and firearms from undercover FBI agents.

Authorities said the public was never in danger from the explosives and weapons, which they said were always under the control of federal officials during the sting operation.

(Reporting By Ros Krasny; Editing by Doina Chiacu)