ALEXANDRIA, Va - Confessed double agent Harold Nicholson, the most senior CIA officer ever convicted of spying, was sentenced Thursday to 23 years and seven months in prison for selling secrets to Russia. Before sentencing, Nicholson, a 46-year-old divorced father of three, told the court he regretted having sold out his country for 2 1/2 years for payments totaling $300,000. He described his sellout as an effort to compensate his children for the time he spent away from them on undercover missions. Jim Wolf, Reuters, posted at 9:32 a.m. PDT Thursday, June 5, 1997