Reuter concession was a contract signed in 1872 between Baron Julius de Reuter (born Israel Beer Josaphat), a British–Jewish banker and businessman, and Nasir al-Din Shah, Qajar king of Persia. The concession gave him control over Persian roads, telegraphs, mills, factories, extraction of resources, and other public works in exchange for a stipulated sum for 5 years and 60% of all the net revenue for 20 years. The concession was so immense that even imperialists like Lord Curzon characterized it as the most complete grant ever made of control of resources by any country to a foreigner.
Why? Source.
Because Iran -- and the Shah -- was broke and the Shah really didn't understand the implication of his concessions. It was an is standard practice to payoff the head honco so as to exploit his people