Spark Energy, a natural gas and electricity retailer primarily in Illinois and California, filed on Thursday with the SEC to raise up to $92 million in an initial public offering. The Houston, TX-based company, which was founded in 1999 and booked $326 million in sales for the 12 months ended March 31, 2014, plans to list on the NASDAQ under the symbol SPKE. Spark Energy initially filed confidentially on April 25, 2014. Baird and Stifel are the joint bookrunners on the deal. No pricing terms were disclosed.