October 20 (SeeNews) - US-based Fluence Energy Inc, an energy storage joint venture of US electricity generation and distribution group AES Corp (NYSE:AES) and German industrial conglomerate Siemens AG (ETR:SIE), is seeking to raise up to USD 744 million (EUR 639.6m) in gross proceeds from its initial public offering (IPO) by selling some 31 million shares.