(Reuters) – Japan’s Sony Corp forecast a much bigger than expected annual net loss of 230 billion yen ($2.14 billion) as it takes a big impairment charge for its struggling smartphone division. It’s the company’s sixth guidance cut under CEO Kazuo Hirai, who took the post in April 2012 promising to revive the storied electronics brand by focusing on mobile, gaming and imaging. Following are key moments from recent years. 2011: * May 26 – Posts 260 billion yen net loss for year to March2011, hit by a tax credit write-off; forecasts 80 billion yennet profit for year to March 2012. …