Gasoline Price Stabilization Act of 2003

Amends the Energy Policy and Conservation Act to cite additional criteria under which a severe energy supply interruption is deemed to exist, including a determination by the President that the increase in the price of petroleum products is: (1) likely to cause a significant adverse impact on the national, State, or regional economy; and (2) a substantial cause of the energy supply reduction is the anticompetitive conduct of either foreign countries or international entities, or producers, refiners, or marketers of petroleum products.

Requires the President, when the price of a barrel of crude oil exceeds $25 on the New York Mercantile Exchange for more than 14 days, to issue a report to certain congressional committees that: (1) states the results of a comprehensive review of the causes and potential consequences of the price increase; (2) provides an estimate of the likely duration of the price increase, based on analyses and forecasts of the Energy Information Administration; (3) provides an analysis of the effects of the price increase on the cost of gasoline at the wholesale and retail levels; and (4) states whether, and provides a specific rationale for why, the President does or does not support the drawdown and distribution of a specified amount of oil from the Strategic Petroleum Reserve.

Directs the Secretary of Energy to establish minimum inventory levels that producers, refiners, and marketers of crude oil and petroleum products must maintain in order to limit the impact unexpected supply disruptions have on prices at the wholesale and retail level.

Amends the Mineral Leasing Act to repeal the authorization for the export of Alaska North Slope oil, and prohibit such exports.

Urges the President to instruct the U.S. Representative to the World Trade Organization (WTO) to file a complaint in the WTO against oil-producing countries for violating their obligations under its rules.