SERVICE CONTROL BIDS FOR AMERICAN SERVICE <Service Control Corp> said it has started a tender offer for all shares of <American Service Corp> at 37 dlrs each. In a newspaper advertisement, the company said the offer and withdrawal rights expire April Nine unless extended. The American Service board has approved the offer, which is to be followed by a merger at the same price. Service Control said the offer is conditioned on receipt of at least 534,806 shares. It said holders of 534,819 shares have agreed to tender their shares under the offer and have granted Service Control an option to buy them at 37 dlrs each.