LAS VEGAS— When it comes to flatscreen televisions, size matters.

At this week’s International Consumer Electronics Show, Sharp Electronics Corp. took the crown for introducing the world’s largest, a behemoth 108-inch liquid-crystal display that most people probably couldn’t fit through their front door.

Sharp and its rivals also announced technological improvements to how LCDs render highspeed movement, cutting down on the staccato image trails that have so far made LCDs less smooth than plasma models.

“LCD TVs have become larger and are now competing aggressively in screen-size segments that were formerly the exclusive domain of plasma and rear-projection televisions,” Sharp chief executive Toshihiko Fujimoto said. “There’s no question that LCD TV is fast becoming the dominant flatpanel technology.”

Last year, South Korea’s Samsung Electronics Co. unveiled what was then the World’s largest flat TV — a 102-inch plasma model.

Sharp and several rival brands such as Samsung, LG Electronics Inc., Toshiba Corp., Royal Philips Electronics NV, Sony Corp., and Matsushita Electric Industrial Co.’s Panasonic said they doubled the frame rate per second on LCD screens from 60 to 120, which makes fast movement seem to go by more smoothly.

Toshiba and Sharp explained this was done by calculating what should go between two frames.

“We take Frame A and Frame B and we create a Frame A-plus-B in between,” Toshiba vice president of marketing, Scott Ramirez, said. “That eliminates that negative that LCD might have had.”

Panasonic’s Andrew Nelkin, vice president of the display group, said improvements to LCD TVs have narrowed, but not closed, the gap in moving-image quality with plasma screens.

“Whether that is 5%, 10%, 20% is still kind of up to the individual viewer,” he said. “To some people any difference is very noticeable.”

Sales of both plasma and LCD TVs have been booming, especially with the advent of high-definition digital broadcasting in the United States mandated to take effect by 2009.

More than a third of American households owned a high-definition television in 2006 and some 55% are expected to own one this year, according to the Consumer Electronics Association.

Sales of flat panel TVs in the United States are expected to total 13.5 million in 2006, with threequarters made up of LCD TVs and the rest plasma, the group said. Total sales are expected to reach nearly 20 million this year and more than 25 million next year, with LCDs continuing to dominate.

But the price tag on gargantuan models still exceeds the average budget.

A 103-inch plasma TV by Panasonic retails for $70,000. LG’s 71-inch plasma costs about $15,000 — an 80% price reduction from a year ago.

Sharp’s monster TV, which will be available in the summer, has not yet been priced, but the company said it was confident it would find a few customers.

“I’m sure we’ll find people who will want to buy a 108-inch TV,” Sharp’s senior vice president of marketing, Bob Scaglione, said. “Believe it or not, a lot of questions came out when we released a 65-inch LCD and now, I wouldn’t call it a mainstream product, but it’s available at retail at $10,999.”

He said some companies might need large panels for signs, professional studios or conference rooms, and “it may trickle down to consumers in the future.”