TOKYO -- The yen's sharp appreciation threatens to undercut profits at major Japanese exporters by more than 1 trillion yen ($9.37 billion) this fiscal year, outweighing any benefits of a stronger home currency for some companies, estimates by The Nikkei show.

Even at exchange rates of 110 yen to the dollar and 125 yen to the euro -- levels on which many companies are basing their fiscal 2016 earnings estimates -- 25 of the country's biggest exporters, including Toyota Motor and Komatsu, would see their combined operating profits fall 1.14 trillion yen on the year owing to currency movements alone.

But the yen has already blown past these levels. At 106 yen to the dollar and 121 yen to the euro, close to current rates, the downward pressure on profits would climb to nearly 1.63 trillion yen. At 105 yen and 120 yen, it would reach almost 1.75 trillion yen -- slightly more than 5% of estimated total fiscal 2015 operating profits at companies that close books in March.

Japan's automakers would feel this blow intensely. At 110 yen to the dollar, the seven leading car companies would see their operating profits knocked back more than 800 billion yen this fiscal year, estimates by The Nikkei show. Toyota, which is particularly vulnerable with respect to the dollar, would take a 400 billion-yen hit. At 105 yen to the dollar, the baseline for many Toyota group members' fiscal 2016 earning estimates, the damage would worsen to 600 billion yen.

Mazda Motor, which exports a high share of its autos from Japan -- about 80% -- might have been looking ahead to profit growth this fiscal year were it not for a rising yen. So would industrial group Mitsubishi Electric, according to Senior Vice President Akihiro Matsuyama. Instead, Mazda expects its operating profit to fall 25%. Mitsubishi Electric is forecasting a 14% decline, despite robust demand for its automation equipment.

For net importers of inventory and supplies, such as retailers and electric utilities, a stronger home currency is a boon. At Tokyo Electric Power Co. Holdings, every 1 yen-rise against the dollar reduces fuel expenditures by about 12 billion yen.

But on balance, a growing yen hurts listed companies' earnings because manufacturers account for more than 60% of total profits. Gains of 1 yen against both the dollar and the euro shaves 0.6% off the combined pretax profits of 200 leading companies, Daiwa Securities reckons. At 105 yen to the dollar and 115 yen to the euro, the cut would amount to 2%, according to Kazuhiro Takahashi, equity strategist at Daiwa Securities.

Japanese exporters built up their resistance to a strong yen amid the currency headwinds that persisted long after the 2008 global financial crisis. In Sony's case, a 1 yen-increase against the dollar in fiscal 2008 meant a 4 billion-yen drop in profit.

But the electronics group took steps to restructure its earnings base, such as increasing dollar-denominated procurement. By fiscal 2011, a strong yen had no effect on its earnings. Now, a 1 yen-rise adds 7 billion yen to Sony's profit. Honda Motor has managed to reduce the impact of the same currency hike from 20 billion yen in fiscal 2007 to 11 billion yen by shifting more production to North America and emerging markets.

(Nikkei)