Technology giant Samsung plans to sell a variation of its flagship Galaxy S4 smartphone that will transmit data at nearly twice the normal speed, the head of its mobile business has said. J.K. Shin, also co-chief executive of the world's biggest technology firm by revenue, said the phone would be sold in South Korea as early as this month. Samsung was in talks with several overseas carriers to begin selling the phone, Shin told the Reuters news agency in an interview at Samsung's headquarters in Suwon, just south of Seoul. He declined to name them. "We'll be the first with the commercial launch of the advanced 4G version of the smartphone," Shin said. The new S4 will use LTE-Advanced 4G technology, an upgrade from conventional 4G called LTE, or long term evolution. LTE-Advanced offers data transmission at up to twice the normal 4G speed. The phones will be powered by Qualcomm chips. A film download that takes three minutes with conventional 4G would take slightly more than one minute, Samsung said. Samsung's shares have lost almost $20 billion since June 7 after analysts cut forecasts for Galaxy S4 sales by as much as 30 per cent on industry data that showed the high-end smartphone market was increasingly saturated. The same problem is hitting sales of the Apple iPhone 5. Shin showed little concern about sales prospects for the S4, which hit stores in late April. The mobile devices division is the company's biggest profit generator. "S4 sales remain strong. It's selling far stronger than the (Galaxy) S III ... and the new LTE-Advanced (4G) phone will be another addition to our high-end segment offerings that ensure healthy profit margins," Shin said. Shin added that the new S4 would be slightly more expensive than the current version. The South Korean firm hopes the addition of hardware offerings such as faster data transmission, along with its widely anticipated move to introduce models with unbreakable or flexible displays, will help it protect margin growth. "As operators seek to provide more data-centric mobile services, I think this will become mainstream 4G technology globally in the coming years," Shin said. Shin also said sales of Samsung's tablet products in the US market jumped 3.3 times since it installed brand shops within Best Buy's stores in April, and is now considering expanding the format in Latin America and Britain.