New York ? Garmin Ltd., best known for its global positioning systems, said Wednesday that its fourth-quarter earnings fell 52 percent as smart phones continued to eat into the market for personal navigators.

The company also issued a weaker-than-expected forecast, as it predicted that sales of global positioning system devices will continue to tumble.

Garmin has struggled to adapt to changing consumer behavior. As smartphones with built-in maps and GPS radios become the norm, sales of navigators, which typically sit on car dashboards, have dropped off. Revenue from these products fell 31 percent during the most recent quarter.

The Swiss company earned $132.9 million, or 68 cents per share, for the period ended Dec. 25. That compares with year-earlier earnings of $278.4 million, or $1.38 per share. Revenue fell 21 percent to $837.7 million from $1.06 billion.

Analysts had expected earnings of 89 cents per share on revenue of $870 million, according to FactSet.

In order to compete with do-it-all smartphones, companies such as Garmin have had to slash prices on their navigators. Some of Garmin’s competitors, such as Navigon AG, have stopped selling navigators in the U.S. altogether.

Garmin attempted to challenge the smart phone market by building one of its own. It partnered with hardware maker Asustek Computer Inc. to make Garmin-branded phones that had GPS radios and ran Google Inc.’s popular Android software. But the company wasn’t able to make them stand out in a crowded field that includes the iPhone as well as popular offerings from Motorola Mobilty Inc., HTC Corp. and BlackBerry-maker Research In Motion Ltd.

In November, Garmin said that it was “winding down” its smart phone business.

As its personal navigators have become less relevant, Garmin has shifted its attention toward other, smaller markets. It makes fitness and outdoor gadgets including watches for runners that record distance and speed, and also sells GPS hardware to plane and boat makers.

During the most recent quarter, revenue in its outdoor/fitness segment increased 15 percent to $171 million, aviation revenue added 10 percent to $71 million and its marine business grew 9 percent to $37 million.

Still, these segments combined generated only $279 million in revenue — half of the $559 million generated from the personal navigation business.

CEO Min Kao said he expects sales of personal navigators to continue falling in 2011, pushing overall revenue lower. The company expects to earn between $2.25 and $2.50 per share this year on revenue between $2.4 billion and $2.5 billion.

Analysts were expecting earnings of $2.59 per share on revenue of $2.55 billion.

In response to the company’s weak results and forecast, Wedbush analyst Scott Sutherland said Wednesday he is reconsidering his price target of $28, which already represents a 14 percent discount from the current trading price. He backed his “Neutral” rating of the company.

Garmin, which is based in Switzerland but has operational headquarters in Olathe, Kan., is finding better results from overseas than in the U.S. In Asia, its revenue grew 46 percent for the quarter, while revenue in Europe rose 4 percent. Revenue in North America was down 30 percent.

For the full year, Garmin had net income of $585 million, or $2.95 per share, compared with $704 million, or $3.50 per share, in 2009. Annual revenue fell 9 percent to $2.69 billion.

Garmin’s stock rose 33 cents to $32.47 after falling to as low as $30.55 earlier in Wednesday trading.