* Sees Q3 EPS $1.25-$1.29 vs est $1.25
* Q2 EPS $1.15 vs est $1.14
* Q2 rev $1.56 bln vs est $1.57 bln
* Says operating margin rose by 56 basis points
July 25 (Reuters) - U.S. auto parts retailer O'Reilly Automotive Inc on Wednesday reported a rise in second-quarter profit as operating margins increased, and forecast third-quarter earnings that slightly topped Wall Street estimates.
The Springfield, Missouri-based company forecast earnings per share of $1.25 to $1.29 for the third quarter, compared with analysts' average forecast of $1.25 per share in a Thomson Reuters I/B/E/S poll.
It expects comparable store sales, which are sales at stores open for at least a year, to increase 1 percent to 3 percent during the three-month period.
For the second quarter, O'Reilly reported earnings of $146 million, or $1.15 per share, compared with a profit of $134 million, or 96 cents per share, a year earlier. Revenue rose 5 percent to $1.56 billion.
Analysts on average expected a profit of $1.14 per share, on revenue of $1.57 billion.
Its operating margin rose by 56 basis points to 15.6 percent.
Comparable store sales increased 2.5 percent in the second quarter, although that was slower than an increase of 4.4 percent reported a year earlier.
The company's shares closed at $90.10 on Wednesday on the Nasdaq.