* Cuts full-year profit forecast to Y48 bln from Y52 bln
* Q2 profit Y3.9 bln vs consensus Y7.3 bln
* Trims chip stepper sales forecast to 53 units from 54
* Stepper product mix less profitable than expected
* Nudges up unit sales forecasts for compact cameras, lenses
* Revises full-year assumed dollar rate to 84 yen (Adds comment, details)
By Isabel Reynolds
TOKYO, Nov 4 (Reuters) - Japanese camera and precision equipment maker Nikon Corp cut its full-year profit guidance on Thursday, as a stronger yen cancelled out the benefit of growing camera sales.
Nikon, which competes with market leader Canon Inc and Sony Corp in digital cameras, fell short of investors' profit expectations for the July-September quarter, despite healthy demand for its cameras and lenses, especially in Asia.
"If it were not for the effect of exchange rates, we would have achieved a double-digit increase in sales and operating profit for the half year," Executive Vice President Ichiro Terato told a news conference, referring to the camera division.
Instead, half-year operating profit at the camera division fell by nearly 16 percent to 22.3 billion yen, while the precision equipment business made a loss.
Despite having shifted most of its camera production overseas, Nikon is being hit hard by a rise in the yen, which is hovering around 15-year highs close around 81 yen to the dollar, eating into the value of the profits it brings home.
Last week, rival Canon beat market expectations for quarterly profit and raised its annual profit outlook after cutting costs.
Nikon posted an operating profit of 3.9 billion yen for the July-September quarter, far below an average estimate of 7.3 billion yen from four analysts, but above the company's own forecast of 2.2 billion yen.
The company also cut its operating profit forecast for the full year to March 2011 to 48 billion yen from 52 billion yen, below an average estimate of 57.8 billion yen in a survey of 22 analysts by Thomson Reuters I/B/E/S.
Nikon revised its assumption of the dollar's exchange rate for the full business year to 84 yen from 91 yen.
In precision equipment, Nikon trimmed its annual sales forecast for steppers, machines that print electronic circuits onto silicon wafers to make computer chips, to 53 units from 54 and said a less-profitable than expected product mix would cut the division's full-year profit by a third.
Rival chip-equipment maker ASML of the Netherlands, the industry leader, beat forecasts with a big rise in third-quarter profits last month and said it should end the year with a record order book.
Shares in Nikon have fallen about 24 percent to 1,552 yen since the beginning of the financial year in April. (Editing by Edwina Gibbs and Michael Watson)