July 13 (Reuters) - Delta Air Lines Inc reported a 20.8 percent fall in quarterly profit as operating expenses swelled, and the airline said it expected passenger unit revenue to rise between 2.5 percent and 4.5 percent in the current quarter.
The company's net income fell to $1.22 billion, or $1.68 per share, in the second quarter ended June 30, from $1.55 billion, or $2.03 per share, a year earlier.
On an adjusted basis, the No. 2 U.S. airline by passenger traffic earned $1.64 per share.
Total operating revenue rose 3.3 percent to $10.79 billion.
The carrier said passenger unit revenue - which compares sales with flight capacity - increased 2.5 percent in the quarter. (Reporting by Arunima Banerjee in Bengaluru; Editing by Saumyadeb Chakrabarty)