NEW YORK (Reuters) -British billionaire Joe Lewis pleaded guilty to U.S. insider trading charges on Wednesday after being accused last year of a scheme that prosecutors said was designed to enrich friends and associates, and apologized to a judge for his conduct. Lewis, 86, pleaded guilty to one count of conspiracy to commit securities fraud and two counts of securities fraud under an agreement with the U.S. Attorney's office in Manhattan. As part of the plea deal, Lewis can appeal if the judge in the case sentences him to prison time, his lawyer David Zornow said.