"That will be the main effect on our sales outlook," finance chief Julian Deutz told journalists on a conference call.

The publisher of Europe's largest daily Bild had earlier said it now saw flat revenue this year compared with a previous forecast for growth by a low single-digit percentage.

Chief Executive Mathias Doepfner also said political and economic instability had increased uncertainty for the rest of the year.

Axel Springer generates about 12 percent of its sales in the United Kingdom, accounting for about 10 percent of its earnings before interest, tax, amortisation and depreciation (EBITDA).

As costs related to those sales are also booked in pounds, Springer does not expect the weak currency to weigh on its earnings for the year and reaffirmed its guidance for a low to medium single-digit percentage rise in adjusted EBITDA.

The publisher's shares were down 2.9 percent at 1006 GMT, one of the worst performers on the STOXX Europe 600 Media index <.SXMP>, which was 1.7 percent lower.

Axel Springer said second-quarter EBITDA, excluding special items, was flat at 147 million euros (£123.31 million), just above consensus for 142 million in a Reuters poll, with estimates of eight analysts ranging from 131 million euros to 149 million.

Sales rose 0.7 percent to 801.9 million euros, just below average expectations for 806 million.

The Berlin-based publisher, which also owns news website Business Insider and last year launched a European version of Politico, is betting on digital products, which now account for 67 percent of revenue and 72 percent of core profit.

Its online classified ads unit has been the main contributor to the transition and is now the company's largest unit in terms of EBITDA.

The classified ads unit booked a 16 percent rise in EBITDA during the quarter to 88.2 million euros. Paid models, which include Springer's magazines and Bild newspaper reported a 21 percent EBITDA decline.

(Editing by Maria Sheahan and Susan Thomas)

By Harro Ten Wolde