The cuts come just weeks after Dong announced the axing of 400 jobs on 20 August.
Dong confirmed the redundancies, with 200 people already gone, will take place throughout the organisation including its wind unit.
Christensen, who was responsible for engineering, procurement and construction and a member of the wind division's executive board, resigned from the Danish company a couple of days ago.
He had worked in various postions throughout the business for more than 27 years. A Dong spokesperson said he left because he felt it was a good time to step down and wanted to try something new.
Christensen said: "I have worked with practically all known energy technologies. These years, the energy sector is going through a rapid development, and for some time, I have considered using my competencies and wide experience in a new role outside of Dong Energy.
"It is always difficult to find the right time for such a decision, but I find that the timing is appropriate now that wind power is facing the opening of a new chapter in the development of the company.
"I am considering a number of different possibilities for the future. Time will show whether it will be in a Danish or an international company."
The job cuts are part of what the company calls a streamlining initiative announced in February, which includes selling its onshore assets to fund offshore development.
Dong CEO Henrik Poulsen said the cuts are "difficult but, unfortunately, also necessary, [in the] process to improve Dong Energy's competitiveness.
"With the agreement to divest our Danish onshore business, we are taking a further step towards the realisation of that plan.
"Our competences and capital will be deployed in offshore wind, where we have a strong and differentiated competitive platform."