(c) General Terms and Conditions of Sale. In order to promote the profitability and efficiency of public procurement, an agency may indicate the terms of the project employment contract in the invitation and ask the successful service provider to become a party to a project employment contract that contains these conditions as a precondition for obtaining a contract. An agency may seek the views of potential tenderers and trade union representatives, advise them and exchange information in order to determine the appropriate terms of a project employment contract for a particular project and to facilitate the agreement of those conditions. On February 6, 2009, President Barack Obama signed Executive Order 13502, which requires federal authorities to prescribe the use of AOPs in federal construction projects costing $25 million or more on a case-by-case basis.  The purpose of this law was to repeal the bush 13202 and 13208 implementing decrees eight years earlier, which had banned administration-ordered ASAs for federally and federally funded construction projects.  Obama`s injunction states that federal authorities can require a PLA if such an agreement achieves federal goals in terms of cost-effectiveness and efficiency. Under the terms of the arrangement, non-unionized contractors can compete for contracts that are subject to SPAs, but they must agree to the different conditions contained in each PLA to win a federal contract and build a project.