In 2003, Ameren acquired Peoria-based CILCORP, Inc. and its leading subsidiary, Central Illinois Light Company, from AES Corporation. CILCORP had traded on the NYSE with ticker symbol CER prior to its acquisition by AES, and by the mid-1990s had become a member of the S&P Small Cap 600 index. CILCO had been another pioneer utility in the region, which had paid a dividend since 1921. By 1996, it had grown to over US$150 million in assets, and carried US$330 million in long-term debt. Following the 2003 Ameren acquisition, that utility began doing business as AmerenCILCO.