noun
sole agency; exclusive distribution
Business term for the exclusive right to sell a product in a particular market or region.
その会社は国内での一手販売権を持っている。
That company holds the exclusive distribution rights in Japan.
独占販売 also means exclusive sales, but 一手販売 emphasizes the sole agency aspect more strongly.
Compound of 一手 (いって, 'one hand' or 'single-handed') and 販売 (はんばい, 'sales'), literally 'single-handed sales', referring to exclusive distribution.