Delta forecast Q2 profit above Wall Street expectations and reported a 31% rise in quarterly profit on Wednesday, boosted by a renewed agreement with credit-card issuer American Express and robust travel demand. The company said it expects profit for Q2 to be in the range of $2.05 per share to $2.35 per share. At the midpoint of the range, the profit forecast was above average analyst estimate of $2.13 per share. The airline forecast total unit revenue, a closely watched performance metric, to increase 1.5 to 3.5% in Q2. <br/>