UPDATE 1-South Africa's Mondi Group H1 profit falls on mill maintenance shutdowns

shutdowns@ (Adds CEO quote, details)

JOHANNESBURG, Aug 3 (Reuters) - Packaging and paper company Mondi Group's half-year underlying profit fell 6 percent after the valuation of its forestry assets in South Africa rose less than the year before and due to the impact of mill maintenance shutdowns, it said on Thursday.

Underlying operating profit fell to 497 million euros ($589 million) in the six months through June from 529 million euros a year ago, Mondi, which is also listed in London, said in a statement.

Its Johannesburg-listed shares fell 2.3 percent in early trade, while the London stock was down 2.5 percent at 0706 GMT.

"Profitability was down on the comparable prior year period, mainly driven by a significantly lower forestry fair value gain in South Africa and the impact of mill maintenance shuts," Chief Executive Peter Oswald said in a statement.

The valuation of its forestry assets in South Africa rose 20 million euros in the period, compared with 48 million in 2016.

In the first half of 2017, Mondi completed a longer than anticipated annual maintenance shutdown at its Syktyvkar mill in Russia, as well as a shutdown at its Swiecie mill in Poland and smaller ones at a number of other mills.

Based on prevailing market prices, it said the full year impact on underlying operating profit of the shutdowns was now estimated at around 90 million euros, up from 80 million euros.

"The second half of the year will be impacted by planned maintenance shuts at a number of our mills and the usual seasonal downturn in Uncoated Fine Paper," Oswald said.

An interim dividend of 19.10 euro cents per share has been declared.

($1 = 0.8445 euros) (Reporting by Nqobile Dludla; Editing by Susan Thomas and Mark Potter)