Federal prosecutors are trying to determine if former Gov. Rod R. Blagojevich and his allies used political muscle to influence student admissions at three state universities. U.S. Attorney Patrick J. Fitzgerald issued subpoenas this week seeking admissions office records from the University of Illinois, Northern Illinois University and Southern Illinois University. The request was related to Blagojevich and three of his co-defendants on criminal corruption charges, William Cellini, Christopher Kelly and Alonzo Monk. The investigation also seeks records related to Antoin Rezko, a Chicago businessman and political operative, who last June was convicted of fraud and bribery. The federal investigation, seeking records from 2002 to 2008, was begun a week after Gov. Patrick J. Quinn appointed a panel to investigate accusations that hundreds of students at the University of Illinois had been admitted because of their families' political connections. 'The governor is aware of the situation at the University of Illinois, and that is why he formed the Admissions Review Commission,' said Robert Reed, a spokesman for the governor. The Chicago Tribune has reported that as many as 800 applicants to the university had been admitted because of political patronage. 'I don't think this federal investigation is greatly different from what the commission is doing,' said a University of Illinois spokesman, Thomas Hardy, 'but we will look to see what documents fall under this subject, and provide them to the U.S. attorney's office.' Melanie Magara, a spokeswoman at Northern Illinois University, said, 'We have done some preliminary investigations of our admissions practices, and we have found nothing wrong.' 