DUBLIN, Sept 6 (Reuters) - Aircraft lessor AerCap on Wednesday said it had agreed a $645 million settlement with Russian state state-controlled airline Aeroflot regarding 17 aircraft and five spare engines that were stranded when Russia invaded Ukraine last year.

AerCap, the world's largest aircraft lessor, in March said it had been approached by Russian airlines and their insurance companies about possible settlements for the stranded planes.

"On September 5, 2023, we received cash insurance settlement proceeds in the total amount of approximately $645 million in full settlement of our insurance claims under the Aeroflot group's insurance policies in respect of the 17 aircraft and five spare engines" on lease to Aeroflot and Rossiya Airline, AerCap said in a stock market filing.

"Effective upon receipt of these insurance settlement proceeds from ... Insurance Company NSK ... we have released our claims against NSK, Aeroflot, Rossiya and their international reinsurers with respect to these aircraft and engines," AerCap said.

It said it had received approval from the U.S. Treasury and Commerce departments for the settlement and said settlement discussions were underway with several other Russian airlines.

AerCap said the amount of a separate $3.4 billion claim against its all risks insurers under "our contingent and possessed insurance policy" has been reduced to approximately $2.75 billion due to the Aeroflot settlement. (Writing by Conor Humphries; editing by Jason Neely and David Evans)