(Adds earnings comparison, stock movement)
By Ernest Scheyder
HOUSTON, July 27 (Reuters) - Exxon Mobil Corp, the world's largest publicly traded oil producer, posted a lower-than-expected quarterly profit on Friday as its production dropped and it spent heavily to upgrade several key refineries.
Shares fell 2.7 percent to $82 in premarket trading.
The Irving, Texas-based company posted second-quarter net income of $3.95 billion, or 92 cents per share, up from $3.35 billion, or 78 cents per share, in the year-ago quarter.
Analysts expected earnings of $1.27 per share, according to Thomson Reuters I/B/E/S.
Production fell 7 percent to 3.6 million barrels per day of oil equivalent.
Earnings from the company's downstream unit, which refines crude oil into gasoline and other products, fell 47 percent, which Chief Executive Darren Woods said was the primary drag on earnings in the quarter.
Exxon said the second quarter featured multiple refinery renovation projects, known as turnarounds, in France, Canada, Texas and Saudi Arabia.
The company plans to hold a conference call to discuss quarterly results on Friday morning. (Reporting by Ernest Scheyder Editing by Nick Zieminski)