BEIJING, July 29 - A Chinese regulator is conducting an anti-monopoly investigation into Microsoft Corp over its Windows operating system, in the latest of a growing number of competition probes that have unnerved Western firms in China.
* Merck up as results beat expectations, but Pfizer slips
SAN FRANCISCO, July 29 - Twitter Inc's monthly active users rose 24 percent to 271 million in the second quarter, as the online messaging service struggles to accelerate its pace of growth.
July 29 - DreamWorks Animation SKG Inc's quarterly revenue almost halved as moviegoers gave a tepid reception to its dragon movie, "How to Train Your Dragon 2", released in June.
(Adds Pfizer, Nobel Biocare, Edison, Millhouse Capital, Bank of Cyprus)
No related earnings announcements are currently scheduled within the next 7 days.