HELSINKI, July 29 (Reuters) - Telecom equipment maker Nokia reported a stronger-than-expected second-quarter operating profit on Thursday and raised its full-year outlook as promised, thanks to a turnaround of its business. The Finnish company’s April-June comparable operating profit rose to 682 million euros ($808.51 million) from 423 million euros a year earlier, beating the 408-million euro mean estimate in a Refinitiv poll of analysts. $1 = 0.8435 euros Reporting by Essi Lehto; editing by Terje Solsvik and Sriraj Kaluvila Our Standards: The Thomson Reuters Trust Principles.