* Subaru soars 6 pct as short-sellers seeing covering positions after earnings - traders
* Exporters sold as earnings disappoint
* SoftBank Group rises to daily-limit high, adds hefty positive points to Nikkei
* Mazda soars after raising forecast
By Ayai Tomisawa
TOKYO, Feb 7 (Reuters) - Japanese stocks fell on concerns about slowing corporate earnings growth, though SoftBank Group allayed some of the anxiety as its shares jumped after the index-heavy firm announced a share buyback and above-expected third-quarter profits.
Subaru Corp was also in the spotlight, rallying 6 percent even though it cut its annual operating profit forecast as the automaker struggled with production issues from a defect in one of its components. Traders said that investors, who had shorted the stock over the past year on concerns about its earnings, covered their short positions. Subaru shares tanked 34 percent last year.
The Nikkei share average dropped 0.6 percent to 20,751.28.
The broader Topix declined 0.8 percent to 1,569.03, with all but one of its 33 subsectors in the red.
Exporter stocks were sold off, with Panasonic Corp falling 3.1 percent, Toyota Motor Corp shedding 1.9 percent and Suzuki Motor declining 2.8 percent.
"Many of the Japanese and U.S. companies have cut their earnings forecasts during this earnings season so investors find it difficult to buy," said Shoji Hirakawa, chief global strategist at Tokai Tokyo Research Institute, referring to bellwether companies such as Toyota, Hitachi Ltd and Panasonic.
In the United States, disappointing revenue forecasts from videogame companies pulled down the overall market overnight.
Going against the grain, SoftBank Group Corp ended 17.73 percent higher at a daily-limit high of 9,962 yen, a level not seen since mid-October after Chief Executive Masayoshi Son unveiled a $5.5 billion share buyback to prop up its share price, which he sees as undervalued.
SoftBank contributed a hefty 165 points to the Nikkei.
Analysts said the big share buyback announcement was the icing on top of SoftBank's robust earnings.
Buoyed by rising valuations of its technology investments, SoftBank Group's operating profit in the October-December quarter rose to 438.3 billion yen from 274 billion yen a year earlier. That handily beat the 225 billion yen average estimate of three analysts polled by Refinitiv which gives a higher weighting to top-rated analysts.
Bucking the weak market, Mazda Motor Corp also surged 6.4 percent after the automaker forecast a full-year operating profit of 80 billion yen, up from a previous forecast of 70 billion yen.
(Editing by Shri Navaratnam)