Former Union minister and senior NCP leader Praful Patel today filed his nomination for the Rajya Sabha election in Maharashtra slated for June 19. Chief Minister Prithviraj Chavan, Deputy Chief Minister Ajit Pawar and a few ministers in the Congress-NCP government in the state were present at Vidhan Bhawan, when Patel filed the papers. NCP leader Tariq Anwar, who was elected to Lok Sabha, has quit his Rajya Sabha seat.