Antitrust regulators released tougher guidelines for merger reviews on Tuesday that could delay transactions by two to three months. The first major changes to the Hart-Scott-Rodino filing process in 45 years, announced by the Justice Department and Federal Trade Commission, require companies to submit additional information that the agencies hadn’t previously requested, according to the proposed rules. “The Agencies acknowledge that the proposed changes require a significant amount of additional information,” the agencies said in a statement.