Billionaire Thomson Family to Buy £25 Million Luxury London Flat

A member of the multibillionaire family behind Thomson Reuters Corp. agreed to buy a high-end London apartment for about £25 million ($34 million), in the latest sign of North Americans bolstering the city’s luxury market.

The Thomson family member — whose exact identity is unclear — agreed to purchase the sprawling single-level flat in Mayfair earlier this year, people familiar with the matter said, asking not to be named as the information is private. A representative for the Thomson family didn’t respond to a request for comment.

The deal, one of London’s most expensive this year, is the latest example ...