The company originally planned to start producing oil in the fourth quarter of next year, with an expected final investment cost of around Nkr12bn ($1.4bn).
It has revised the investment guidance for the project to less than Nkr9bn ($1.07bn).
Wintershall Europe and Middle East Exploration and Production board executive member Martin Bachmann said: “In challenging times, we have kept a clear focus on smart engineering and sharp project management.
“The experience gained in the Maria project will serve as a blueprint for our Nova development, previously known as Skarfjell, and worldwide.”
Located in the Haltenbanken area of the Norwegian Sea, the Maria field is connected via subsea tiebacks to the Statoil-operated Kristin, Heidrun and Åsgard B production platforms.
The plan for development and operation (PDO) was submitted to the Norwegian Ministry of Petroleum and Energy in 2015.
Maria Project head Jens Balmer said: “By using tried and tested components, and working closely with excellent suppliers, we have delivered a field that will continue to return value to us, our partners, and the whole of Norway, for many years to come.”
With a planned 25-year lifespan, the field has estimated recoverable reserves of around 180 million barrels of oil equivalent (boe).
Wintershall Norge holds the operatorship of the licence with a 50% interest, while Petoro holds a 30% stake and Spirit Energy owns the remaining 20%.