Cadogan Estates has given Mayfair Capital Investment Management a mandate to invest £600m in assets outside London.
The 300-year-old estate has established a new fund, Cadogan Income Properties, in a bid to meet 10-year inheritance tax charges.
Since April around £50m has been spent so far on property, including £15.8m on a retail unit and four fully let industrial warehouses at the 36 Business Park in Barnsley from Harworth Group.