The estanco, or estanco de tabacos, was the state tobacco monopoly introduced into Spanish America in the second half of the eighteenth century, starting with Peru in 1752. It was easily the most profitable of the imperial monopolies. After independence some countries established the estanco as a state monopoly. Perhaps the most famous was the Chilean tobacco monopoly, established in 1824. The Chilean government farmed out the estanco to the Valparaíso trading house of Portales, Cea, and Company, which agreed to assume responsibility for a £1 million loan secured in London in 1822 by the Bernardo O'Higgins government. When payments on the loan were not met, the government rescinded the contract in 1826, to the considerable resentment of Diego Portales, a partner in the trading house. Portales and several like-minded associates (some connected with the estanco contract) formed a political group that demanded a stronger government and an end to the liberal approach favored by the regimes of the 1820s. The estanqueros, as these politicians became known, took a leading role in the Conservative capture of power in 1829–1830, following which Portales became the most powerful figure in Chile.
Kinsbruner, Jay. Diego Portales: Interpretative Essays on the Man and Times.
Villalobos R., Sergio. Los estancos en Chile. Santiago, Chile: Fiscalía Nacional Económica: Centro de Investigaciones Diego Barros Aran, 2004.