ZURICH, Sept 13 (Reuters) - The following are some of the main factors expected to affect Swiss stocks on Thursday:
* Swiss Prime Site AG has agreed to buy Wincasa AG from Credit Suisse Group for an undisclosed sum, the company said as it announced a rise in first-half profit of 18.3 percent to 180.3 million Swiss francs.
* BKW said net profit for the first six months of 2012 amounted to 112 million francs, corresponding to an increase of 24.1 percent.
* Lifewatch has filed an antitrust lawsuit against Highmark BCBS, the BlueCross Blue Shield Association, and several other BlueCross BlueShield entities alleging damages of over USD 60 million.
* Producer/Import price data for August due at 0715 GMT
* The Swiss National Bank announces its monetary policy decision, including its target for the 3-month Swiss franc LIBOR at 0730 GMT.