UAL Corp., parent of United Airlines, warned that its earnings this year will be well below expectations because of higher fuel and labor costs. The news sent the company's shares plummeting $9.88, or 13%, to close at $64.89 on the NYSE. UAL forecast earnings for the year at between $7 and $9 a share. Analysts surveyed by First Call/Thomson Financial had forecast earnings of $9.76 for the year. The company said it anticipates a 2% to 4% increase in revenue, which will be outweighed by an expected 6% rise in costs.