TIMELINE-Sony's recent profit warnings

(Repeats to wider coding; reformats)

Sept 17 (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 March 2011, hit by a tax credit write-off; forecasts 80 billion yen net profit for year to March 2012.

2012:

* April 1 - Hirai named as CEO.

* April 10 - Sony cuts net loss forecast to 520 billion yen from a previous forecast of 220 billion yen.

* May 10 - Posts record annual loss of 455 billion yen.

* August 2 - Cuts operating profit forecast to 130 billion yen from 180 billion yen, blaming a strong yen and weak economies.

* Nov 1 - Books small July-Sept operating profit of 30.3 billion yen, helped by the sale of a chemicals business; keeps full-year operating profit guidance at 130 billion yen.

2013:

* Oct 31 - Posts July-Sept net loss of 19.3 billion yen; cuts operating profit estimate for year to March 2014 to 170 billion yen from 260 billion yen, as TV operation is again loss-making.

2014:

* Feb 6 - Again cuts full-year operating profit forecast - to 80 billion yen from previous 170 billion yen; Hirai seeks to isolate a TV business that has lost $7.8 billion in a decade to speed up decisions on future strategy.

* May 1 - Cuts operating profit forecast - this time to just 26 billion yen - for the year that ended in March.

* May 14 - Announces 135 billion yen restructuring costs for year to March 2015, on top of the 177.4 billion yen spent in the previous year; sells loss-making Vaio PC and disc storage businesses; forecasts the restructuring costs will push it to a 50 billion yen net loss for the year to March 2015 - a likely sixth loss in seven years, totalling almost 1 trillion yen.

* July 31 - Posts April-June operating profit of 69.8 billion yen, helped by the sale of a technology facility in Japan.

* Sept 17 - Forecasts full-year net loss of 230 billion yen as it takes a 180 billion yen impairment charge for its struggling smartphone division; says it will not pay a dividend this year - for the first time since listing in 1958.

(Compiled by Teppei Kasai; Editing by Ian Geoghegan)