SEOUL - Samsung Electronics, the world's top technology firm by revenue, estimated operating profit nearly doubled in January-March from a year ago, boosted by sales of its flagship Galaxy smartphones and its Note mini-tablet and phone.

The South Korean group, which out-sold global smartphone rivals last year, is set to consolidate its market position with new products, including a revamped Galaxy S, in the next few months.

Samsung, which will release its full quarterly results on April 27, estimated its January-March operating profit at a record 5.8 trillion won ($5.15 billion) versus a consensus forecast of 5.0 trillion won from analysts surveyed by Thomson Reuters I/B/E/S. It estimated sales at 45 trillion won.

Samsung shares have risen by a quarter so far this year, and hit a life high of 1.351 million won ($1,200) on Wednesday. Over the same period, shares in smartphone rival Apple have soared by more than half, taking the California-based firm's value to above $582 billion - more than three times that of Samsung. ($1 = 1127.2750 Korean won)

(Reporting by Miyoung Kim; Editing by Ian Geoghegan and Jonathan Hopfner)