"Over the last few days Joe Paterno has experienced further health complications. His doctors have now characterized his status as serious," a statement said.

The Paterno family said it would have no further comment on the situation and asked that their privacy be respected "during this difficult time."

Paterno's family disclosed on November 18 that he had been diagnosed with treatable lung cancer. He has been in and out of hospital since and was treated with radiation and chemotherapy.

Paterno, the winningest coach in major college history, was ousted after a former assistant coach was charged with serial child sex abuse. University trustees fired Paterno because he failed to tell police what he had been told about the alleged abuse.

(Reporting and Writing by Greg McCune; Editing by Cynthia Johnston)