COMPANY TOWN : Sony’s 1st-Quarter Profit Soars 91% in Foreign Exchange Gain : Earnings: Entertainment group performs strongly, but income plummets at other units due to stiff competition.

TOKYO —  Group profit at Sony Corp. soared 91% in its first quarter, ended June 30, but the rise was largely due to a gain from currency transactions. Sony’s core business continued to struggle, although its pictures group had its second consecutive profitable quarter after taking a $2.7-billion write off last year, the company said Thursday.

Group net profit jumped to $82 million in the April-June quarter from $42.9 million in the same period a year earlier, the electronics and entertainment giant said.

Sony said the gain included a foreign exchange gain of $329 million in the quarter, much larger than a similar gain of $82.4 million in the year-ago period.

Group operating profit, based on Sony’s core business operations, fell steeply because of stiff competition in audiovisual equipment markets and the sharp appreciation of the yen, which hurt export earnings, the company said.

“The appreciation of the yen damaged profits severely,” Sony Managing Director Sumio Sano told a news conference.

Operating profit plunged to $172 million from $349 million.

For the full business year to next March 31, Sony predicted it would return to the black with a group net profit of $450 million, compared to a loss of $3.22 billion last year.

Sony suffered a big group loss in the 1994-95 business year because of troubles at its U.S. movie-making operation--including its Columbia and TriStar studios--which caused it to take a $2.7 billion write-off of goodwill, the value of the operation based on expectations of future income.

On Thursday, Sony shares traded on the New York Stock Exchange fell 62.5 cents to $56.50.

Within the entertainment business, Sony’s pictures group suffered a 10.1% drop in sales to $635 million because of the rise of the yen, Sony said. On a local currency basis, however, sales were up 13%.

Operating income for entertainment, which includes pictures and music, jumped 127% for the quarter, to $115.7 million, over the same period a year earlier. The rise was attributed to the success of movies including “Bad Boys,” “Legends of the Fall,” and “Little Women,” and the strength of television shows such as “Ricki Lake.”

Sony’s music group posted 2.2% sales growth to $1.21 billion, helped by sales of more than 6 million copies of Michael Jackson’s “HIStory” CD during the quarter, Sony said.