Rebel groups MLC, RCD-Goma, and RCD-ML each made their own deals with foreign businessmen for cash and/or military equipment. Battlefields most commonly centered on areas that held a lot of diamond and coltan potential and foreign armies' occupation of the eastern region was maintained by illegal resource exploitation. For $1 million per month rebel group RCD-Goma gave a coltan monopoly to SOMIGL which they in turn poured into efforts to gain control from RCD-ML of mineral-loaded land. To get fast cash to gain control of government land, the DRC gave a diamond monopoly to Dan Gertler's International Diamond Industries (IDI), which was supposed to pay the Congolese government $20 million for it. But it paid only $3 million, yet continued to extract diamonds from the region and sell them internationally. Upon request of the IMF and World Bank the DRC liberalized diamond trade, after which IDI threatened to sue for breach of contract, a contract they themselves did not honor.