Oct. 29, 2009 (United Press International) -- A British man was acquitted Thursday of the murder of his wife, a top executive at a cell phone company, in a jealous rage but was found guilty of manslaughter.

Jurors deliberated for seven hours in Winchester Crown Court before deciding Alisdair Sinclair had "diminished responsibility" for his wife's death, The Daily Telegraph reported.

Sally Sinclair, 40, was stabbed more than 30 times with several kitchen knives as the couple's two children watched. Mrs. Sinclair, a top executive at Vodafone (NYSE:VOD) , had filed for divorce in July and had admitted to her husband she had been unfaithful to him.

Mrs. Sinclair's mother, Nicki Alford, was angry about the verdict, The Times of London reported.

"He didn't just kill her, he annihilated her," she said after the verdict was announced.

Alisdair Sinclair said he was depressed before he killed his wife last year because of deaths in his family and that he was drinking and smoking heavily and taking antidepressants. He had not worked for about a decade, instead caring for the children.

Police found Mrs. Sinclair's body in a pool of blood on the kitchen floor of their rented mansion near Amport in Hampshire.

Alisdair Sinclair was scheduled to be sentenced Friday.