Think ETFs was acquired by Van Eck in January from previous owners Binck Bank and Flow Traders. At the time of the deal, Think's senior management retained a stake in Think.
Rozemuller will remain based in Amsterdam and will report directly to Van Eck's found Jan van Eck in New York.
Van Eck now has three offices across Europe including Frankfurt and Switzerland.
Speaking to ETF Stream, Rozemuller said the original acquisition by Van Eck would enable Think ETFs to grow faster in Europe.
"Both Think and VanEck had a healthy ambition to grow in Europe, we believe that combining forces that ambition will become more achievable in the coming years," he added.
The acquisition increases the amount of assets under management within the European UCITS regime to $2.6bn.
"The acquisition of Think has created synergies on both sides and we benefit from the fact that Think has created a strong reputation with its high quality products," said van Eck. "We will use this, along with the Think management's expertise, to benefit our customers in Europe."
"Think ETFs and VanEck share the same values and philosophy - to represent the interests of the client for the long term. Together we will assume an even stronger position in Europe."
It has been a busy past 12 months for consolidation within the European ETF sector. Just last week, Lyxor bought Commerzbank's European arm and late last year, ETF Securities' commodities ETF business was snapped up by WisdomTree while the rump equities operation went to Legal & General.
The Van Eck buyout will propel the Think business further with expansion plans. In an interview with ETF Stream late last summer, Rozemuller said that the Netherlands ETF market was at a "tipping point". "People, both professional and retail, are becoming more knowledgeable on ETF's and start to use them more and more. But we certainly lag the developments in the US, hopefully we'll catch up in the coming years."
"I hope we will be able to realise our European expansion plans, and I hope we will be able to continue to educate (retail) investors. Not only on ETF's, but also on the way they can help building a solid investment portfolio for the long term."
Speaking this week, he said he believes the consolidation that has taken place so far in the European ETF space is likely to increase further in the months ahead.
"I do believe that the European ETF space will become even more competitive and for some players that could mean M&A activity," he said, although he shied away from making hard any detailed predictions.