Japan's ailing electronics giant, Sony Corp, warned investors on Thursday it was heading for a worse-than-expected USD2.9 billion annual loss, revealing the daunting task ahead for its incoming chief executive, Kazuo Hirai.

The company, overtaken by more innovative rivals such as Apple and Samsung over the past decade, gave the forecast in its third-quarter results, surprising a market that had been expecting a full-year loss of barely half that amount.

Sony said it expected to make a loss of JPY220 billion (USD2.88b) for the year to March, its fourth straight year of red ink, including a hefty $1.2 billion operating loss for the third quarter and a steep slide in sales at its troubled TV unit.