BUZZ-Aviva Plc: Full-year operating profit beats forecast
** British insurer' U.S.-listed shares up 6 pct at $17.35 premarket
** 2014 operating profit rises 6 pct, slightly higher than forecast
** To pay final dividend of 12.25 pence per share, up 30 pct
** Proposed merger with Friends Life Group Ltd to complete next month
** Up to Wednesday's close, Aviva (Other OTC: AIVAF - news) 's U.S. shares had gained 5.5 pct in 12 months