Merck said second-quarter net profit slumped to 85.5 million euros ($117.9 million) from 528.5 million euros in the year-earlier period after a gain from the sale of assets last year was not repeated and as the company wrote down the value of some inventory after buying Serono.
Analysts surveyed by Thomson Financial News had forecast net profit to decline to 30.8 million euros.
Sales fell to 1.72 billion euros from 1.07 billion euros a year earlier, the company said in a statement. The average analyst forecast was at 1.76 billion euros.
Earnings before interest and tax were at 94.6 million euros, compared with 573.5 million euros a year earlier, it said.
Merck said it sees full-year operating profit gaining more than 20% from last year.
It cautioned that the euro's current strength against the dollar may have an impact on full-year sales.