* Q1 operating profit 337 bln yen vs consensus of 302 bln yen
* Excluding effect of Gungho purchase, profit jumped 35 pct
(Adds in underlying operating profit figure)
TOKYO, Aug 8 (Reuters) - Japanese wireless operator SoftBank Corp said its first-quarter operating profit fell 15.6 percent, pulling back after a large one-off gain in the same period a year earlier related to the acquisition of an online game company.
But SoftBank beat forecasts, booking 337.6 billion yen ($3.3 billion) in operating profit for the April-June quarter compared with an average forecast of 302 billion yen from four analysts, according to Thomson Reuters StarMine.
Excluding the effect of last year's Gungho Online Entertainment Inc acquisition, SoftBank's operating profit posted a 35 percent increase from last year.
The company reiterated its operating profit target for the year to March 2015 of 1 trillion yen, unchanged from its previous guidance and in line with the adjusted 1.08 trillion yen it earned the year before.
SoftBank said its 2014/15 forecast includes no temporary gains, versus 253.9 billion yen in business combination-related gains for the year earlier.
SoftBank's U.S. mobile carrier Sprint Corp this week dropped its bid to acquire No. 4 U.S. carrier T-Mobile U.S. Inc after regulatory resistance showed no signs of softening despite months of lobbying. (1 US dollar = 101.7300 Japanese yen)
(Reporting by Teppei Kasai and Edmund Klamann; Editing by Edwina Gibbs)