LCD and plasma TVs require few repairs during the first three years of use, and buyers would be wasting their money during the holiday shopping season if they bought extended warranties on the highly reliable devices, Consumer Reports found in a study released Friday.

The consumer review firm's Annual Product Reliability Survey, featured in the upcoming December issue, found that the flat panel sets overall had a 3% repair rate. Rear-projection TVs, on the other hand, were found to be much more repair prone than its two rivals.

Panasonic's 50-inch TH-50PZ700U plasma model was named Consumer Reports' best flat-panel TV ever tested. Overall, Panasonic liquid crystal display and plasma sets had a 2% average repair rate.

Among LCDs, Dell, which recently stopped selling its own brand of TVs, and Hitachi were among the less reliable brands, as were Philips plasma TVs. Aside from Panasonic, other brands with low repair rates included Sony, Samsung, Toshiba and JVC in LCDs; and Pioneer and Samsung in plasmas.

Among the tiny percentage of sets with problems, most repairs were free, presumably because they were covered by the manufacturer's standard warranty. The few respondents to CR's survey who paid for repairs spent an average of $264 on LCD sets and $395 on plasmas. "This new reliability data reinforces Consumer Reports long-standing advice that consumers skip the extended warranty when buying a flat-panel TV," CR said in a statement.

Among rear-projection TV vendors, Toshiba and RCA had the most repair-prone sets that were based on digital light processing technology. Hitachi had the worst record for repairs on sets based on LCD technology.

The report found about a quarter of the repairs involved replacing the bulb, with many failures occurring early in a set's life and covered by the standard warranty. Respondents who paid for repairs spent $300 on average. Rear-projection sets overall had an average 18% repair rate.

Despite the relatively high repair rate, CR still advised consumers not to buy the often expensive extended warranty and service contracts. Nevertheless, consumers who insist on buying an extended warranty for a rear-projection set should consider one if they want to buy a repair-prone TV because of its low price.

In addition, an extended warrant might be considered if the person plans to use the TV for 5,000 hours within the time covered by an extended warranty and it covers bulb replacement. Many bulbs have a life expectancy of 5,000 hours.

Finally, the warranty should not cost more than the $200 to $300 it costs for a new bulb or 15% of the TV's price, whichever is less.

Meanwhile, CR also found that prices for high-definition TVs are expected to drop about 30% on average this year than in the 2006 holiday shopping season. Plasma TV prices are expected to shrink the most, with 42-inch models falling below $1,000 by the end of the year, and some 50-inch models selling for less than $1,500.

Flat-panel high-definition TVs were at the top of people's wish list for Christmas, according to a recent national survey by the Solutions Research Group. Second was a Windows-based notebook, followed by a digital camera.