Aug. 24 (Bloomberg) -- Nippon Sheet Glass Co., the world's biggest supplier of car windows, had the second-biggest gain in Japan's Nikkei 225 Stock Average after increasing its profit forecast because the yen weakened against the pound.

The stock gained 23 yen, or 3.8 percent, to 635 yen in Tokyo. The number of shares traded was double the full-day average of the past year.

The yen's declines against the pound, euro and U.S. dollar are boosting the value of overseas earnings converted into Japanese currency. Nippon Sheet Glass acquired Pilkington Plc of the U.K. last year in its biggest takeover, making Europe the largest of the Japanese glassmaker's three business regions.

``The currency is a big factor for the earnings revision,'' said Masao Yoshida, an analyst at Okasan Securities Co. in Tokyo. ``The key point is how the company will generate synergies with Pilkington to expand earnings.'' He rates the stock ``neutral.''

Net income will rise to 53 billion yen ($455 million) in the 12 months through March 2008, 18 percent more than an earlier estimate of 45 billion yen, Nippon Sheet Glass said yesterday after the market closed. The company also increased its full-year sales target by 2.4 percent to 850 billion yen.

Europe accounted for more than half of Nippon Sheet's total revenue and represented about 70 percent of operating profit -- sales minus the cost of goods and administrative expenses -- in the April to June quarter, the company said.

Nippon sheet Glass provides windshields and side windows for automakers including DaimlerChrysler AG and Bayerische Motoren Werke AG of Germany and Toyota Motor Corp. and Mazda Motor Corp. of Japan.

To contact the reporter on this story: Masumi Suga in Tokyo at msuga@bloomberg.net.

Last Updated: August 24, 2007 03:31 EDT