Utility Southern Company edges down after announcing $1.75 bln mandatory convertible

** Shares of utility Southern Company SO.N down 0.3% at $93.52 early Thurs as it seeks capital raise

** Atlanta, Georgia-based SO announces 35 mln equity units at $50 for $1.75 bln in public offering

** SO intends to use some net proceeds from the 3-year mandatory convertible offering to partially repurchase 4.50% convertible notes due June, 15, 2027

** Remainder earmarked for repayment of short-term debt and general corp purposes

** BofA and Barclays joint bookrunners for offering

** SO has ~$109 bln market cap

** Stock has gained ~7% YTD compared to ~3% rise in S&P 500 Utilities sector .SPLRCU

** Avg rating among 24 analysts is "hold"; median PT of $96.50 down from $100 a month ago, per LSEG data