Panasonic is preparing to repeat its CES show-stopper of a couple of years ago with the unveiling of the largest flat-panel screen manufactured to date, according to a Japanese media report.

The company will unveil a 150-inch PDP television at the International Consumer Electronics Show (CES) that begins in Las Vegas on January 6, the Yomiuri Shimbun newspaper reported earlier this week.

Two years ago, Panasonic stole the lead on two South Korean rivals, Samsung and LG, by unveiling a 103-inch PDP screen. The two Korean companies had previously shown 102-inch panels. With the new screen Panasonic captured by an inch the title of "world's biggest flat-screen" and held that title until CES 2007 when Sharp unveiled a prototype 108-inch LCD (liquid crystal display) panel. Panasonic's display remains the biggest PDP in the world but not the biggest flat panel.

Panasonic declined to comment on its specific plans for CES 2008 but did say that say it is "putting its efforts in developing larger screens" because the 103-inch was well received.

If the 150-inch screen does appear at CES it is likely to be an early prototype from the company's ¥280 billion (£1.25 billion; US$2.5 billion) state-of-the-art PDP production line in Amagasaki, in western Japan, that is due to start production sometime in the year from April 2008. The new production line is a step more advanced than Panasonic's current line and should be able to make more advanced PDPs at lower costs.

The cost savings come from the line's use of larger sheets of mother glass - the initial glass sheets on which several panels are produced. Panasonic's current line can handle mother glass from which eight 42-inch panels can be produced while the new production line will accept sheets from which twelve 42-inch panels can be made.

Panasonic won't disclose the exact size of the sheets but simple arithmetic shows they need to be roughly 2 meters by 3.4 meters to produce twelve such screens. To make a 150-inch PDP panel would require a sheet of glass about the same size.