** Jefferies upgrades energy provider Southern Company SO.N rating to "buy" from "hold" and cuts PT to $100 from $102

** Shares of SO up marginally in premarket trading; new PT is 13.3% upside to stock's last close

** Brokerage says company's execution risk diminishes with regulatory certainty secured via rate case settlement and financing already underway

** "Although we don't expect a guidance raise yet, a rebase could occur as the company pivots into the higher-growth" - Jefferies

** Brokerage adds that the current valuation reflects SO as a premium utility, but does not adequately account for one of the sector's largest and most liquid names seeing accelerating earnings growth

** 7 out of 20 brokerages rate the stock "buy" or higher, 12 "hold" and 1 "sell"; their median PT is $94.50 - data compiled by LSEG

** As of last close, SO shares up 7.3% YTD

(Reporting by Sumit Saha in Bengaluru)

((Sumit.Saha@thomsonreuters.com;))