Demi Moore and Ashton Kutcher to divorce

Demi Moore is ending her marriage to Ashton Kutcher.

The 49-year-old actress announced her divorce plans to The Associated Press today, saying she was doing it with "great sadness and a heavy heart".

She said that "as a woman, a mother and a wife, there are certain values and vows that I hold sacred, and it is in this spirit that I have chosen to move forward with my life".

Moore added that it was a trying time for her and her family, and asked people to respect her privacy.

Moore and Kutcher married in September 2005. Their relationship became tabloid fodder in recent months as rumours abounded about Kutcher's alleged infidelity.

Moore and Kutcher frequently used Twitter to communicate with each other as millions of fans followed.

The day before their sixth wedding anniversary, Moore ominously quoted philosopher Epictetus: "When we are offended at any man's fault, turn to yourself and study your own failings. Then you will forget your anger."

The couple created the DNA Foundation, also known as the Demi and Ashton Foundation, in 2010 to combat the organised sexual exploitation of girls around the globe.

They later lent their support to United Nations efforts to fight human trafficking, a scourge the international organisation estimates affects about 2.5 million people worldwide.

Moore was previously married to actor Bruce Willis for 13 years. They had three daughters together - Rumer, Scout and Tallulah Belle - before divorcing in 2000.

Willis later married model and actress Emma Heming in an intimate 2009 ceremony at his home in Parrot Cay in the Turks and Caicos Islands which was attended by their children, as well as Moore and Kutcher.