LONDON — Sir Angus Ogilvy, a businessman who married Queen Elizabeth II's cousin Princess Alexandra but kept a low profile as a member of the extended royal family, died Sunday of pneumonia at 76, Buckingham Palace said.

Ogilvy, whose family long had close ties to the royals, shunned the limelight. His 1963 Westminster Abbey wedding, though, was a major event, attended by 2,000 guests and televised around the world.

His widow, Princess Alexandra of Kent, is the queen's first cousin — their fathers were brothers. The two were close friends growing up, and he often served as her dancing partner. They had two children, James, 40, and Marina, 38.

Ogilvy, who worked as an investor, was the second son of the 12th Earl of Airlie and Lady Mary Coke, who was the daughter of the third Earl of Leicester. He studied at Eton and Oxford University and earned a reputation in London financial circles as a clever, hardworking investor.

He made unwanted headlines in 1973, when he was forced to quit the board of the mining and finance company Lonrho when it was accused of violating sanctions against the African country Rhodesia, now called Zimbabwe.

A government report later said Ogilvy had been negligent and shown "weakness and indecision" by failing to rein in the company's chief executive.

Ogilvy contended that the criticisms of him were unfounded.