July 31 (Reuters) - Shares in Industrie De Nora tumbled on Monday after the Italian electrode maker posted lower first-half core earnings and said full-year revenues were likely to come in at the low end of expectations.

The group said in a statement it now expected 2023 revenues at the low of its 900-950 million euros ($990 million-$1.05 billion) forecast range.

Its Milan-listed shares fell as much as 8.6%, and closed at 18.77 euros ($20.69) per share, down 6.8%.

Presenting first-half results, De Nora said its core earnings - or adjusted earnings before interest, taxes, depreciation and amortization (EBITDA) - fell to 86.1 million euros from 102.3 million in the same period of 2022.

Finance chief Massimiliano Moi blamed the drop on a slowdown in the water technologies business, particularly related to swimming pools, which saw strong growth in the pandemic and also benefitted last year from an exceptional rise in prices indexed to the cost of noble metals.

"In terms of EBITDA margin we are absolutely confident in a good performance, while on absolute terms - depending on the revenue performance - EBITDA could be on the low part of the range," Moi said during a call with analysts, referring to 2023 adjusted EBITDA guidance of 175-185 million euros.

($1 = 0.9071 euros) (Reporting by Luca Fratangelo, Romolo Tosiani, Editing by Sharon Singleton and Mark Potter)