Japan on Monday began test broadcasts of satellite television programmes in 4K, as major firms including Sony and Sharp bet on the super high-definition technology to rescue their embattled TV units.

A consortium of major broadcasters, TV manufacturers and communications firms rolled out the test across the country of 128 million, a move that comes with Tokyo's backing as it looks to boost the competitiveness of the world's number three economy.

The technology has four times the resolution of standard high-definition televisions, but high prices have so far limited commercial sales of 4K-equipped televisions.

"I think it's wonderful that 4K broadcasting through a satellite will be available in households nationwide for the first time in the world," said Yoko Kamikawa, vice minister of the Internal Affairs and Communication Ministry, as the test started.

"We will continue working towards a full-fledged 4K broadcast and 8K test broadcasting" in 2016, she added.

Public broadcaster NHK has already developed 8K technology, which has quadruple the resolution of 4K, or 16 times the sharpness of current high-definition TVs.

The country is hoping to unveil 8K technology commercially before Tokyo's hosting of the 2020 Olympics.

Other countries are eyeing the cutting-edge technology -- which can also be used in fields such as medicine and education -- upping the ante for Japan as it tries to showcase its technological prowess.

"Various countries are accelerating trials and the launch of new services using (4K and 8K) technologies," said Katsuaki Watanabe, a former Toyota president and chairman emeritus of NexTV-F, which is leading the consortium behind the test.

"Japanese industry has to survive in this severe environment," he added.

Private broadcasters are reportedly cautious about the huge investment required to film and broadcast 4K-quality programmes.

But struggling Japanese electronics makers are pinning their hopes on sales of 4K televisions as tough overseas competition and razor-thin margins in the lower end of the business dent their finances.

Last month Sony president Kazuo Hirai pointed to stronger sales of its 4K ultra high-resolution TVs, which tend to have better profit margins than lower-end models, as a way to rescue its loss-making television unit.