(AP) -- A research firm says shipments of LCD flat-panel TVs will fall this year from the year before, the first such decline since the popularity of such TVs took off in 2006.

The firm iSuppli says lingering economic concerns and slow price declines will crimp shipments to 31.9 million sets this year. That's down 1.2 percent from 2009.

Apart from the economy, it's possible U.S. are finally having their appetite for new TVs satisfied.

The Consumer Electronics Association says about two-thirds of households now have high-definition sets.

LCD is the most popular type of TV, accounting for more than 90 percent of U.S. sales.