The firm of Grieve and Bremner, a Scottish-based enterprise involved in the Newfoundland trade, was formed by Walter Grieve (1809-1887) and Alexander Warren Bremner (d.1886) circa 1863. Grieve had been a partner in Baine, Johnston & Company but withdrew in 1855 to form Walter Grieve and Company. He subsequently entered into the partnership with Bremner, and purchased the Slade property at Trinity. In 1869, Grieve and Bremner leased the Garland premises at Trinity from John Bingley Garland, giving the firm control of the chief mercantile properties in the town.

During the 1860s, Walter Grieve lived primarily in Greenock, Scotland, while Bremner managed the firm at Trinity. Robert Sweetland Bremner, Alexander's son, succeeded him at Trinity. The firm engaged in all aspects of the trade, although Baine, Johnston and Company or Walter Baine & Company may have handled the firm's imports and exports of goods and fish. These St. John's firms periodically sent one of their steamers to the seal hunt from Trinity, no doubt crewed with many of Grieve and Bremner's regular fishing clients. Sealing appears to have been an important aspect of the Grieve and Bremner business since the old Slade property was used primarily for landing seal pelts and producing seal oil.

Alexander Bremner died in 1886, followed by W. R. Grieve in 1887, bringing an end to the business. Bremner bequeathed his Catalina premises and property to his sons, Robert S. and Alexander Hugh. Robert also received œ10,000 as his father's share of the net profits from the Grieve and Bremner business. The monetary bequest probably helped Robert purchase from Grieve's trustees the Grieve and Bremner premises at Trinity, where he pursued the fish trade until becoming insolvent in 1900.