The company, created from the merger of the oil and gas divisions of German chemicals group BASF and Russian billionaire Mikhail Fridman's LetterOne, now expects to produce 640 thousand barrels of oil equivalent per day (mboe/d).
It had previously expected to produce 635 mboe/d in 2019.
The company, which has said it wants to be ready for an initial public offering (IPO) by mid-2020, appointed Deutsche Bank this year as the global coordinator for the listing.
"Wintershall Dea made good progress during our first full quarter since the merger. Strong operational performance gave us confidence to revise our full-year production guidance to 640 mboe/d," Chief Executive Mario Mehren said.
Third-quarter production rose 6.1% to 613 mboe/d, while earnings before interest, tax, depreciation, amortization, and exploration expenses (EBITDAX) fell more than a quarter to 708 million euros ($780 million).
The decline was due to the significantly weaker commodity price environment, with prices for Brent and European gas down 20% and 60% respectively from a year earlier, the company said.
Wintershall Dea, owned by BASF and LetterOne in a 67-33 split, also cut its forecast for capital spending capex in 2019 to about 1.6 billion euros (£1.37 billion) from up to 1.7 billion previously.
Equity capital markets bankers have said it may choose to wait until 2021 to launch its listing since volatile markets have prompted a slew of firms to pull plans for IPOs this year.
Bankers said the company also needs to take into account oil markets and geopolitical factors including the Nord Stream 2 gas pipeline - a project opposed by Washington - that Wintershall is backing financially when deciding the best timing for a listing.
(Reporting by Christoph Steitz and Arno Schuetze; Editing by David Clarke)