Following the move, which takes effect from 1 January 2018, Vestas' current president of central Europe, Nils de Baar, will lead the new merged unit from its headquarters in Hamburg, Germany.
The president of northern Europe, Klaus Steen Mortensen, will leave Vestas by "mutual consent", the manufacturer said, but the Malmo office will "remain an important location in Vestas' sales efforts".
The move was part of its strategy "to ensure an agile organisation that adapts to market and customer needs", Vestas said.
"Among other things, reorganising the SBUs intends to create simpler and more agile SBUs with faster and clearer decision-making."
In February 2017, Vestas reorganised its Asia-Pacific sales units, splitting it in two, with one for China, and one for the rest of the region.
Vestas' chief sales officer Juan Araluce said: "With mature markets moving to auctions and competitive tenders, it is imperative that our business model reflects and supports our customers' needs in being successful in the market.
"Since joining Vestas, Nils de Baar has increased sales and strengthened project execution across Central European markets. He is the right person to lead the merger and position Vestas strongly."
Mortensen has been Vestas' president of northern Europe since 2007, including a six-month spell also as interim president of central Europe in 2014.
Under his leadership in February 2016, Vestas secured the 1GW order from the Statkraft-led consortium for the Fosen project in Norway.