Mozambique was a Portuguese colony, but these stamps were issued by the Mozambique Company. They have a separate entry in SG, and presumably in Scott. Stamps were issued from 1892 to 1941.
The Mozambique Company, in Portuguese the Companhia de Moçambique, was a royal company in the Portuguese colony of Mozambique, that had the concession of the lands that include the present provinces of Manica and Sofala.
The company was established in February 1891 with a capital stock of about 5 million dollars obtained from financiers from Germany, the United Kingdom and South Africa. Isaacman and Isaacman report that the firm was capitalised at 40,000 pounds (not $5 M), and that British and French capital quickly predominated.
The concession was granted for a period of 50 years, during which the company could not only exploit the resources and existing manpower (partly through the Chibalo system of forced labour) but also grant subconcessions. The company was granted the exclusive right to collect taxes, but was itself granted a 25 year tax holiday. In return the Portuguese state would receive 7.5% of the company's profits and 10% of the sold shares. The company was also required to settle 1000 Portuguese families, and provide education and public administration in its territory. [from Wikipedia]
Philatelic information can be found in this link:
http://www.filatelia.fi/articles/mozambique.html