Sony Corporation, which has been making a steady comeback in its electronics and entertainment divisions, was hit hard Monday when it was announced that it would share the costs with Dell Inc. for the recall of 4.1 million laptop computer batteries that may explode in flames. The recall, expected to cost upwards of a quarter billion dollars, followed a report in the Wall Street Journal on Monday observing that such batteries pose a particular threat to airliners. The recall would be the largest in the history of the consumer electronics business, reports said. Nevertheless, shares in Sony rose 1.5 percent higher at midday today (Monday). In an interview with Bloomberg News, Mitsuhiro Osawa, an analyst at Mizuho Investors Securities Co. in Tokyo, said, "Market reaction to the news has been weak because it is difficult to measure the impact of the recall."