This excerpt taken from the OMI DEF 14A filed Mar 9, 2007.
An individual shall be eligible to participate in the Plan if the individual (i) has attained age 18, (ii) is employed by the Company or a Related Company (defined in Section 16 herein) in a capacity that is classified as full-time or part-time plus on the payroll system of the Company and (iii) has been in the continuous employ of the Company or a Related Company for at least 30 days. An individual who has satisfied the requirements of the preceding sentence shall continue to be eligible to participate in the Plan during the individuals continued employment by the Company or a Related Company, including any period that the individual is absent from work on account of vacation or a duly authorized leave. An individual who has satisfied the requirements of this Section 2 and who elects to participate in the Plan in accordance with Section 4 is referred to as a Participant. Any Participant ceasing to be so employed shall be considered to have withdrawn from the Plan in accordance with Sections 14 and 15. Subject to the foregoing, the Committee shall have full and final authority to determine the persons who shall be eligible to participate in the Plan.