National Mortgage and Agency Company of New Zealand Limited owned a nationwide stock and station agency business originally intended to invest directly in New Zealand pastoral activities and lend to other participants in that industry.

By the 1960s as well as the export of wool and meat and dealing in livestock it provided grain and seed merchandising, wholesale grocery services including wines and spirits and arrangement of property and other real estate sales.

National Mortgage and Agency Company of New Zealand Limited was formed in 1877[1] to: The shares were quoted on the London Stock Exchange for the first time on 14 August 1877.

Perthshire-born George Gray Russell (1828–1919), a London ship and insurance broker, came to New Zealand in late 1864 and set up in business as a general merchant selling from premises in Dunedin's Stafford Street: brandy, fencing wire, nails and corrugated iron, oats and timber and other goods.

Content to delegate the necessary authority to young Ritchie Russell regularly travelled widely from Otago up to South Canterbury and down to Southland dealing with clients and noting investment and business opportunities.

Aware that NMA would want to invest in an existing business Russell and Ritchie hung back from direct discussion of possibilities but William Dymock in Dunedin, general manager of National Bank of New Zealand, was a useful conduit for the very slow communications between interested parties (when a delivery in as little as 74 days became occasion for delight).

On 1 February 1878 the column City Intelligence in The Times included this statement: "The National Mortgage and Agency Company of New Zealand Limited has made an arrangement with the firms of Russell, Le Cren and Co., of London and Russell, Ritchie and Co., of Dunedin and Timaru, New Zealand, for the transfer of their businesses to the company.

[12] On 31 October 1973 NMA Wright Stephenson changed its name to Challenge Corporation Limited.