The FTC aggressively investigates potentially anticompetitive mergers and nonmerger conduct in the oil industry and prosecutes when appropriate. Sometimes, an investigation of a proposed merger reveals that a transaction would generate efficiencies that would enhance competition and benefit consumers, or that it would not increase the likelihood that the post-merger firm would be able to increase prices, either unilaterally or collusively. Similarly, some nonmerger investigations may reveal that the conduct under examination passes muster under the antitrust laws because it would not entail collusion with competitors or a unilateral abuse of market power, and that it would likely benefit (or simply not affect) consumers.

The FTC's investigations include examining allegations of horizontal price-fixing, vertical price-fixing, price discrimination, and predatory pricing, as well as gasoline nonprice and merger investigations. The agency has reviewed practices and allegations directly focusing on gasoline pricing in a number of instances, and conducted analyses of whether anticompetitive behavior might explain gasoline price irregularities. The FTC now conducts a monitoring project that has deep roots: the agency investigated West Coast crude oil prices in the early 1980s, gasoline prices in the spring of 1989, West Coast gasoline pricing practices in the late 1990s to 2001, and Midwest gasoline prices in 2000. In addition, pursuant to Congressional directives, the Commission issued a report in May 2006 on its investigation of gasoline price manipulation and of the pricing of gasoline following Hurricane Katrina. The Commission's intensive investigation unearthed no evidence that petroleum companies were acting to manipulate supply in order to raise gasoline prices. As for the post-Katrina pricing inquiry, the Commission identified 15 firms that met the technical definition of price gouging established in the Congressional legislation that mandated the investigation, but reported that regional and local market conditions explained the price increases in virtually all such instances.

From 1973 to May 2007, the FTC conducted approximately 190 oil industry investigations that resulted in at least 44 enforcement actions, including final orders, complaints issued or filed in court, and matters in which a transaction was abandoned after initiation of a Commission investigation.