Discussions of a merger between United Airlines and American Airlines have emerged, potentially creating a dominant player in the airline industry. United Airlines CEO Scott Kirby proposed the merger to U.S. President Donald Trump in February, but experts warn of significant antitrust challenges due to route overlaps and concerns about higher fares. Shares of American Airlines rose 5% in premarket trading, while United Airlines shares increased by 2%, as investors viewed the merger as a potential positive despite the backdrop of rising fuel costs linked to the U.S.-Israeli conflict with Iran. Both airlines have seen their stock prices decline recently, with American down 14.1% and United off 10.4% since the conflict began. The merger could reduce the number of major U.S. carriers from four to three, raising concerns about competition and pricing power, which could ultimately lead to higher fees for consumers. Regulatory scrutiny is expected from both federal and state levels, with recent lawsuits against other mergers indicating a growing trend of opposition to consolidation in the industry.