When the Administrator shall determine and declare it to be advisable to insure against a certain risk or risks with commercially procured insurance, with the approval of the Committee, then, as to such risk or risks, the Insurance Coverage Office shall provide for the placement of such insurance as shall be necessary with duly accredited and qualified commercial insurers. The purchase of all new insurance policies and the renewal of all existing policies shall be by open bid procedure under rules and regulations promulgated by the Administrator calculated to permit the free forces of market competition to operate to the economic benefit of the state insurance coverage program.