TOKYO (Reuters) - Sony Corp shares fell more than 4 percent to hit the lowest in almost three years on Friday after the electronics maker announced a recall of 438,000 Vaio portable computers due to possible overheating that could burn users.
Sony has been dogged in recent years by recalls of laptop computer batteries due to concerns they would overheat and catch fire. Dell Inc, Apple Inc and other top PC makers recalled 9.6 million Sony batteries in 2006, costing the Japanese firm 51 billion yen ($481.5 million).
The company said the impact on its earnings from the latest recall would be limited. But some market participants voiced concerns about Sony's reputation because the recall hit one of its main businesses and the company was slow to report the defect.
Mitsushige Akino, chief fund manager at Ichiyoshi Investment Management, said Friday's fall in the share price was likely triggered by a firmer yen and a decline in U.S. shares, but the recall could damage the Sony brand if the company finds further such defects.
"If these things pile up and reveal that Sony's structurally weak, then its brand value will definitely be hurt," he said.
Sony said the problem in the Vaio laptops, produced between May 2007 and July 2008, is related to irregularly positioned wires near the computer's hinge that can cause a short circuit and overheating.
The company considers the PC business as one of its seven pillars and aims to expand it to a 1-trillion-yen ($9.4 billion) business by the year ending in March 2011.
Sony spokesman Shinichi Tobe said the company sees a limited impact on its earnings from the recall -- one of the biggest in computers since 2006.
Tobe said the company had first learned of the Vaio wiring trouble in August 2007 and had replaced parts individually for those computers that were affected.
It reported the problem to the Japanese authorities last month when there were more than 200 cases worldwide and moved to a voluntary recall, announced on Thursday. Some pointed out that the gap in timing was too much.
"It is not appropriate, considering how big the issue is," Toshihiro Nikai, the minister of economy, trade and industry, told reporters when asked about Sony's handling of the case.
One Tokyo-based analyst, who declined to be named, said the latest recall could even hurt Sony's battery business.
"As far as reliability and the delay in taking action, this case links to its past lithium battery recall," the analyst said. "One would wonder if Sony would be OK when both of the businesses are expanding.
"This will likely cast a shadow over Sony's earnings targets in the medium to long run."
Sony shares had shed 4.2 percent to 3,880 yen as of 0355 GMT after touching 3,850 yen, the lowest since November 2005. The Nikkei average was down 2.5 percent.
Reporting by Sachi Izumi; Editing by Chris Gallagher