UPDATE 1-Nintendo's Q2 profit falls 52 pct, cuts forecast

* Q2 operating profit 64 bln yen vs 90 bln yen consensus

* Cuts annual forecast by a quarter to 370 bln yen

* Shares end down 1.1 pct before results (Recasts with quarterly figures, adds details)

TOKYO, Oct 29 (Reuters) - Nintendo Co Ltd (7974.OS) reported a 52 percent slide in quarterly profit on Thursday, hurt by slowing demand for its flagship Wii videogame console and the strong yen, and slashed its full-year forecast.

Demand for Nintendo products has cooled as rival Sony Corp (6758.T) has bolstered its line-up of console games, and as Apple Inc's (AAPL.O) iPhone has become a popular platform for handheld games.

Nintendo's earnings, like those of other Japanese exporters, have been blunted by the stronger yen JPY=, which eats into overseas profits.

Nintendo, which also faces stiff competition in the videogame market from Microsoft Corp (MSFT.O), posted an operating profit of 64 billion yen ($709 million) in the July-September quarter, compared with 133 billion yen a year earlier.

That was also lower than an average of 90 billion yen in a poll of four analysts by Thomson Reuters I/B/E/S.

Reuters calculated the quarterly figure by subtracting Nintendo's first-quarter results from the first-half figures released on Thursday.

Nintendo cut its operating profit forecast for the year to March 2010 by a quarter to 370 billion yen, ending a three-year run during which it booked a record profit on booming demand for its Wii console and DS portable device.

Analysts are expecting a full-year profit of 442.8 billion yen, according to Thomson Reuters I/B/E/S.

In September, Sony's Playstation 3 usurped Nintendo's Wii to become the top-selling U.S. video game console for the first time since its release, according to research group NPD. [ID:nN15316311]

Shares of Nintendo finished down 1.1 percent ahead of the results. The stock has declined about 28 percent so far this year, compared with a 14 percent rise in the Nikkei 225 .N225 share average. (Reporting by David Dolan)