Samsung Electronics, the world's largest maker of smartphones, memory chips and flat screens, estimated Friday a fresh quarterly high of operating profit in the second quarter this year due to robust sales of smartphones, including the new flagship model Galaxy S4.

The preliminary operating profit was estimated at 9.5 trillion won (8.36 billion US dollars) in the April-June period, Samsung said in a statement. The figure topped the prior record high of 8. 84 trillion won in the fourth quarter of 2012, and was up 8.2 percent from three months earlier.

Sales were estimated at 57 trillion won in the three months ending June 30, up 7.81 percent from the previous quarter.

Samsung did not unveil its estimate for net profit and a breakdown of each division. The final results will be announced later this month.

The record profit was attributable to brisk sales of Galaxy S smartphone series. The sales of Galaxy S4, the latest version of the series, was estimated to be over 20 million units during the quarter.

"Sales of Galaxy S4 were estimated at 20.5 million units during the quarter, missing market expectations. However, it was the first time in Samsung's history that a single model breached the 20 million mark," said Greg Roh, an analyst at HMC Investment & Securities in Seoul.

Combined smartphone sales, including previous models such as Galaxy S3, were estimated at 74.5 million units, up 5.7 percent from three months earlier.

Market watchers, however, said the recent fall in Samsung shares was overdone. Samsung shares sank over 15 percent at one time from the initial price of this year after JP Morgan warned slowdown in Samsung's smartphone sales in June 7 report.

"Risks of weak Galaxy S4 sales and the Fed's plan to taper quantitative easing are indeed negatives to the stock, but we still believe the recent pullback is overdone," said James Song, an analyst at KDB Daewoo Securities.

Song noted that Samsung was best-positioned to dominate the global smartphone market given a broad product mix, brand and marketing power as well as stable supply chains of parts and materials.