** J.P.Morgan continues to favor the "heavyside" sub-sector among European building materials, though notes its outpeformance over the "lightside" names might moderate
** In its latest review, it upgrades Italy's Buzzi BZU.MI to "overweight", which rises around 6%, and maintains Germany's Heidelberg HEIG.DE as its top pick
** JPM cites cheaper valuation for Buzzi compared to sector staples like Heidelberg and Holcim HOLN.S, and high exposure to Germany
** In the "lightside" space it upgrades Sika SIKA.S to "neutral" citing the stock's underperformance
** France's Saint-Gobain SGOB.PA remains JPM's key "lightside" pick as it flags valuation upside on strategy execution and an upcoming volume increase
(Reporting by Enrico Sciacovelli)
((Enrico.sciacovelli@thomsonreuters.com))