A federal judge yesterday ordered ex-Qwest Communications International CEO Joseph Nacchio to report to prison in Pennsylvania by March 23 to begin serving a sentence for insider trading.

Nacchio will serve the six-year prison term at the minimum-security prison camp at Schuykill federal prison at Minersville, Pa.

A jury convicted Nacchio in 2007 on 19 counts of insider trading for illegally selling $52 million worth of stock six years earlier, after company insiders warned him that Qwest could not meet its financial targets.