Samsung Electronics, the world's top maker of memory chips and smartphones, estimated on Friday its October-December profit would jump 73 percent to a life-time high, aided by one-off gains and record-smashing sales of smartphones.

The South Korean firm, which surged past Apple as the world's top smartphone maker in the third quarter, is quickly building on its supremacy with sleek designs and a rich product line-up, while the latest models from the likes of HTC, Nokia and BlackBerry maker Research in Motion struggle to interest consumers.

Its handset division is now Samsung's biggest earnings generator, raking in record profits.

Samsung is also weathering a squeeze at its bread-and-butter memory chip unit with new revenue sources such as mobile processing chips and high-end OLED displays. Key rivals are increasingly turning to Samsung for components to power their tablets and smartphones.

The South Korean firm estimated its quarterly operating profit at 5.2 trillion won ($4.5 billion), compared with a consensus forecast of 4.7 trillion won by analysts surveyed by Thomson Reuters I/B/E/S.

The result would top Samsung's previous record profit of 5.0 trillion won earned in the second quarter of 2010 and is up 22 percent from the preceding quarter.

One-off gains expected in the fourth quarter include around 500 billion won from the sale of its hard disk drive business to Seagate Technology, and reduced mobile provisions involving royalty payments, according to analysts.

Even excluding one-off gains, these are very solid results against a weak industry outlook, said Lee Seung-woo, an analyst at Shinyoung Securities.

Samsung is likely to continue record-breaking earnings this year as earnings from flat screens and memory chips will improve, making up for any potential slowdown in handset growth rates. I'd expect profits to grow by another 5 trillion won this year.

Smartphone shipments are forecast at a record 35 million in the fourth quarter, up one quarter from the preceding three months, when it first surged past Apple as the world's top smartphone vendor.

In 2012, its smartphone sales are expected to rise to as high as 170 million units, according to BNP Paribas and Korea Investment & Securities, the most bullish street view, from an estimated 95 million last year, powered by a diverse product portfolio that spans high-end Galaxy models to cheap phones using Samsung's own bada software.

Its latest Galaxy Note model, which runs on fast fourth-generation (4G) networks, is touted by some followers as a phablet as its 5.3-inch display and powerful dual-core processor makes it work as both a tablet computer and smartphone. Its successful debut in some European and Asian markets during the year-end holiday season has raised hopes for a solid U.S. launch in coming months.

Samsung, the world's biggest technology firm by revenue, estimated fourth-quarter sales at 47 trillion won. The company will provide detailed earnings later this month.

Shares in Samsung, Asia's most valuable technology firm with a market value of around $150 billion, touched a record high of 1.11 million won this week. It is the best performing stock among major global peers, rising 29 percent over the past six months. Apple has gained 21 percent, Sony Corp tumbled 35 percent, Nokia fell 16 percent and HTC lost 50 percent during the same period.

(Reporting by Miyoung Kim; Editing by Matt Driskill and Jonathan Hopfner)