When two firms want to merge, or to transfer enough assets to affect a market change, they must file a notification with the U.S. Justice Department under regulations attached to a statute called the Hart-Scott-Rodino law. Under HSR, as it is more commonly known, the firms that wish to merge or make the transaction must provide the initial details of the sale, as well as details about their own operations, according to anti-trust experts. That initial filing with the Justice Department starts a 30-day clock running in which the Justice Department studies the deal, talks to the companies, talks to the market and evaluates it. For a certain number of deals, smaller or less complicated ones, the regulators can make what is known as an early determination and approve the merger before the 30 days are complete. However, for others, the Justice Department can make what is known as a "second request" for information. This second request is generally much more far reaching, the experts say, and can often take between six to nine months to complete as, unlike the initial filing, it does not have a time limit. Although the anti-trust evaluation process is not public like the process of collection comments on a government regulation, the experts said it does involve a good deal of input from the public. Justice anti-trust staff can request information from competitors, customers and other interested parties, and other parties can volunteer information and opinion. The entire goal is to try to discern how the merger will eventually impact the customer downstream, the experts maintained.