A City banker who strangled his unfaithful wife in a jealous rage because she had demanded a costly divorce was cleared of murder yesterday.

Neil Ellerbeck, 46, showed no emotion as he was instead found guilty of manslaughter by a jury who did not believe that he intended to kill her.

The former chief of global investment at HSBC Asset Management had secretly recorded more than 120 hours of Kate Ellerbeck’s sexually explicit telephone calls before killing her at their North London home.

He discovered that she was having at least two affairs and planned to divorce him. Despite having amassed nearly £1 million, he feared that she would take half the family’s money.

In November last year Ellerbeck, who weighed 15st, strangled the mother of his two children at their £600,000 home in Enfield after a row about whether to send their daughter to a private school.

The Old Bailey heard that the slightly built, 8st woman had been having an affair with their son’s tennis coach, a former chef at the Ritz, and a childhood sweetheart.

Ellerbeck, who was working long hours and who was described as controlling, claimed he had acted in self-defence and had merely wanted to “calm her down” after a “vicious row”. He will be sentenced today.

Mrs Ellerbeck, 45, had started having an affair with Patrick McAdam, her son’s South African tennis coach, two years before her death. She also had a close relationship with an old schoolfriend, Martin Perry.

Ellerbeck, who earned £136,000 before bonuses, bugged her phone calls for 14 months and kept more than 127 hours of recordings, found at his office in Canary Wharf.

He also suspected that Giuliano Vilardo, a former chef at the Ritz, was his wife’s third lover.

When she told her husband that she wanted to split up in November last year, he replied, “I’m not going anywhere”, and threatened to turn their two children, aged 10 and 13, against her. He had also siphoned off money from the family bank account to keep cash from her if they did separate.

On the morning of November 14, after dropping their daughter off for an entrance exam at a prestigious school, they argued about Mrs Ellerbeck’s suggestion that their daughter could attend a local comprehensive if she failed the exam.

While the prosecution said that he strangled her and left her for dead, Ellerbeck insisted that he had merely put his hand underneath her chin to pin her down and believed she was still breathing when he left the house.

He then picked up his daughter, saying her mother had “gone shopping”, before sending a text message to his lover, Julie Ring, saying what a beautiful morning it was and that he was “smiling”. He then bought a lottery ticket, returned home and said that he found his wife face down in the hall.

A post-mortem examination revealed that she died from asphyxia and compression of her neck after “moderate to severe” force. A pathologist said that she had been choked for at least 20 to 30 seconds.

Ellerbeck told the court: “I just wanted to keep her down until she calmed down. I was pushing her face away from biting me. It was a case of constantly applying and releasing pressure all the way through.”

Brought up in Cheshunt, Hertfordshire, Ellerbeck went into international finance at Chase Manhattan bank and stayed there when it merged with JP Morgan in 2000. Six years later he was headhunted by HSBC to look after a £60 billion portfolio.

The couple married in 1994, three years after meeting on a train. While he pursued his career, Mrs Ellerbeck brought up the children virtually single-handed and spent much of her free time at her gym. It was there that she ran into her old “soulmate” Mr Perry, in 1997. She told him during one phone call: “All I want is to be loved. Isn’t that what everybody wants?”

Mrs Ellerbeck, a former oil company travel co-ordinator, was independently wealthy and just a few months before her death inherited £310,000, half of her father’s estate.

In an impact statement, her sister Susan Reid said the loss of her “kind, funny and generous” sibling had been an unbearable nightmare.

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