By Karlee Weinmann (June 13, 2013, 1:52 PM EDT) -- European buyout firm BC Partners is barreling toward a $4 billion-plus acquisition of academic publisher Springer Science & Business Media GmbH, sources told Reuters on Thursday. The firm is the last bidder standing after KKR & Co. LP and Providence Equity Partners dropped out of the running for Springer ahead of a deadline earlier this month. Springer's current owners, EQT Partners AB and the Government of Singapore Investment Corp., had been eyeing a $4.6 billion price tag for their publisher unit, but Reuters reported that they were willing to bend — and that BC would max out its offer at $4.2 billion. EQT and GIC recently unveiled plans to list Springer in Frankfurt sometime over the summer in an initial public offering that would raise more than $1 billion, but that maneuver was widely seen as a way to grease prospective buyers' offers for the company to seal the firms' preferred full exit. A decision on the BC buyout could come as early as this week....