Samsung CEO JK Shin has announced impressive sales for the company in its march for smartphone dominance, following rumours sales were actually faltering.

The company has sold 40 million Galaxy S4 units since the device's launch six months ago, Shin revealed in a recent meeting with South Korean media.

The new sales figure follows up from word of 20 million Galaxy S4 sales in the first two months and then another report noting 30 million sales in four months. Fast forward another two months and Samsung has reached its new milestone of 40 million.

It's a pretty impressive feat and beats Samsung's previous record of selling 40 million Galaxy S III units after seven months. The plastic design of Samsung, which many pundits have come to mock, obviously isn't having any trouble selling on the international market.

But reports have noted Samsung isn't satisfied with sales of the Galaxy S4 (even at 40 million) and that the company was aiming much higher. In turn, Samsung has reportedly moved its Galaxy S5 launch date up to January 2014, rather than later in the spring like years past.

It's still early days, but according to reports we can expect Samsung to drop its traditional plastic design and go for an all-metal chassis like HTC did with the HTC One. This has long been a complaint for Samsung hardware. While speedy, the plastic build is annoying in the eyes of some customers. An Exynos 5430 64-bit CPU and 16-megapixel camera with optical image stabilisation are also expected.

Even if it did miss internal goals, the Galaxy S4 and rest of Samsung's mobile line are bringing in some serious cash for the company. Samsung said earlier this month that in the last 90 days it raked in 10.1 trillion won (roughly £5.8 billion) in operating profit, compared to 8.06 trillion won in the year ago quarter. Total revenue sat at 59 trillion won, up from 57.46 trillion won in the same quarter last year.