[JURIST] US District Judge Sim Lake on Thursday sentenced former Dynegy [corporate website] executive Gene Shannon Foster to 15 months in jail, and former accountant Helen Sharkey received a 30-day sentence for helping co-defendant James Olis defraud investors of over $500 million. Olis, another former executive, received an unprecedented 24-year sentence [JURIST report] which was rejected [PDF opinion] by the Fifth Circuit Court of Appeals. Lake was also expected to resentence Olis Thursday, but instead said that he would wait until hearing testimony from prosecution and defense witnesses on whether Olis should be deemed to be responsible for any investor loss. Lake hinted that Olis will likely receive a minimum term of six years when resentenced. The three were indicted on conspiracy charges for attempting to disguise debt as incoming cash flow in statements to investors; Olis was the highest-ranked defendant and the only defendant to plead not guilty. AP has more. The Houston Chronicle has local coverage.