By Steve Goldstein

LONDON (Dow Jones) -- Bleak news came from two European consumer-electronics firms on Tuesday, with portable-navigation-devices maker TomTom warning on sales and operating profit and computer-mouse maker Logitech International reporting a 70% profit slide for its fiscal third quarter.

TomTom said it now expects fourth-quarter portable navigation devices, in both Europe and North America, to fall one million units short of estimates, and also said it's looking to write down the value of a mapping firm it bought over the summer.

The rival of Garmin (GRMN) said its market share, however, was "strong," at 46% in Europe and 24% in North America. In the third quarter, TomTom had a 45% market share in Europe and more than 20% in North America.

Still, the company said it would have to lower its revenue and margin guidance. After previously estimating annual sales at 1.75 billion to 1.85 billion euros on an operating margin between 20% and 24%, TomTom now expects sales of 1.66 billion euros to 1.68 billion euros on margins between 19% and 20%.

It's the second time that TomTom has lowered sales guidance for 2008.

TomTom also said it's carrying out an impairment review of Tele Atlas, the digital-map maker it bought in June for 2.9 billion euros after outbidding Garmin.

"TomTom is in the process of carrying out an impairment review and our preliminary assessment is that due to the changed macro environment we can no longer fully sustain the full valuation of the acquired business of Tele Atlas as established at the time of the acquisition," the company said.

The warning didn't exactly leave investors floored as the recession in the U.S. and Europe hits consumer-electronics makers around the globe. The stock, in fact, rose nearly 8% on Tuesday, though it's down more than 85% over the past 12 months.

Separately, peripherals producer Logitech (LOGI) issued its full results after a warning in early January, with the Swiss-American firm reporting a 70% drop in third-quarter profit.

For the quarter ended Dec. 31, Logitech earned $40.5 million, or 22 cents a share, compared with $133.6 million, or 71 cents, in the year-earlier period. Sales fell 16% to $627.5 million from $744.2 million.

Hurting gross margin were "a significantly stronger dollar and a retail environment that was highly promotional, particularly in the Americas," President and Chief Executive Officer Gerald P. Quindlen said in a statement.

The executive added: "All indications point to an even weaker retail environment in the coming months. Consequently, our plans assume that in [the fourth quarter] we will see year-over-year declines in sales, operating income before restructuring charges, and gross margin that are similar to or worse than the year-over-year declines" of the third quarter.

Analysts at Dutch broker SNS Securities said that looking at Logitech's results, TomTom's warning probably was due more to flagging prices than to volume.

"Although investors may be worried about the first quarter, especially given Logitech's statements about that quarter, there may also be a sense of relief that TomTom has been able to generate an (operating) margin of between 19% and 20%," they noted.

Investors weren't as pleased with Logitech, with the stock shedding 9% to take 12-month share-price losses to 55%.

Sales missed analyst estimates by 10% and its operating profit fell nearly 50% below analyst views.

"Logitech is clearly hit badly by the economic downturn as consumers hold back tightly on spending. As no end is currently seen to the crisis, we expect negative news flow to continue and will likely see several quarters of negative sales and profit development," said analysts from Swiss brokerage Vontobel.

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