Tiffany's quarterly results topped Wall Street estimates on Tuesday on strong demand for its jewelry in the Americas and China, prompting the luxury retailer to raise its full-year profit forecast.

Tiffany's shares rose 4.2 percent to $135.15 in premarket trading after the company said it expected full-year earnings per share to be between $4.65 and $4.80, up from $4.50-$4.70.

Under Chief Executive Alessandro Bogliolo, Tiffany has been reaping the benefits of a shift in focus to price-conscious younger clientele by selling less expensive fashion jewelry and introducing high-end everyday home items such as $350 gold straws and $1,500 gold paper clips.

The company also recently unveiled Paper Flowers, its new floral jewelry collection made of platinum and diamonds.

Net sales in the Americas, which accounts for nearly half of the company's total sales, rose 8 percent to $475 million. Sales in Asia Pacific grew 28 percent.

The company traditionally benefits from tourist spending in the United States with its flagship New York store generating almost 10 percent of annual sales, but it underlined that the gains this time in both those major regions were driven by spending by locals.

After years of falling sales, mainly due to intense competition from online players such as Blue Nile, Tiffany has been investing significantly to develop its website and boost its marketing and store presentations.