Noun
asiento (plural asientos)
A treaty or pact, in Spanish contexts.
Moreover, Louis sent troops to the Spanish Netherlands to evict Dutch garrisons and secure Dutch recognition of Philip V. In 1701, Philip transferred the asiento (the right to supply slaves to Spanish colonies) to France, alienating English traders. Source: Internet
The issue was finally settled by the 1750 Treaty of Madrid in which Britain agreed to renounce its claim to the asiento in exchange for a payment of £100,000. Source: Internet
While the Portuguese were directly involved in trading enslaved peoples, the Spanish empire relied on the asiento system, awarding merchants (mostly from other countries) the license to trade enslaved people to their colonies. Source: Internet