§ 604. Eligibility conditions. A claimant shall be eligible for benefits under this title if he or she works less than his or her normal hours in a week for his customary employer, and that employer has reduced or restricted the claimant's weekly hours of work, or has rehired a claimant previously laid off and reduced his or her weekly hours of work from those previously worked, as the result of a plan by the employer to stabilize the work force by a program of sharing the work remaining after a reduction in total hours of work and a corresponding reduction in wages, provided the program requires not less than a twenty percent nor more than a sixty percent reduction in hours and wages among the work force. A claimant receiving supplemental unemployment compensation benefits, as defined in section five hundred one (c) (17) (D) of the internal revenue code of nineteen hundred fifty-four, shall not be eligible hereunder. Any employee who was otherwise eligible for benefits under this title but was denied benefits during the period beginning October first, two thousand one and ending on December first, two thousand one because more than five percent of his or her wages were derived from piece work, shall be entitled to make a retroactive claim for such benefits provided such claim is filed within sixty days of the effective date of this sentence.