In the handling of these goods, a variety of important economic functions are performed by the marketing system. Grain and grain products are moved from the raw products producers, processed into desired forms, delivered to the desired locations, and, through the storage function, made available to consumers at the desired time. Grain-marketing channels are the various agencies or institutions through which grain products flow from the producer to the final consumer. The major marketing functions performed by port terminals include buying, selling, short-time storage, financing, risk taking, and assembling and blending grain in shipload volumes to accommodate the specification of foreign grain buyers. Integration tends to reduce the length of marketing channels and to increase the economic control, or marketing power, of those firms involved. Privately owned grain companies and regional grain-marketing cooperatives expanded rapidly through acquisitions during the decade of the 1970s until the early 1980s.