** Shares in Metso METSO.HE drop around 7% after the Finnish mining equipment maker posted Q2 adjusted EBITA 15% below expectations
** The group cites negative sales mix and additional costs from the Enterprise Resource Planning (ERP) implementation
** Analysts at J.P. Morgan and Jefferies note lower adjusted EBITA margin of 14.1% against 16.9% year ago
** "Metso's margin improvement story may have reached a plateau," Jefferies says, even though the ERP costs were mostly one-off
** Metso is among the worst performers on STOXX 600 index .STOXX
(Reporting by Anna Chaberska)
((Anna.chaberska@thomsonreuters.com;))