Ramada Resorts, built on a five-acre land, was managed by Aitken Spence Hotels before the takeover.
The hotel has 64 standard rooms and 30 cabanas, three restaurants and two bars, an Aitken Spence Hotels spokeswoman said.
Aitken Spence Hotel Holdings is one of the largest leisure groups in Sri Lanka.
Before the takeover of Golden Sun, the group had seven hotels under the Aitken Spence Hotels and Resorts brand and another three resorts under its luxury brand, Heritance.
Aitken Spence also owns or manages five hotels in India, six hotels in the Maldives Islands and five hotels in the Gulf sultanate of Oman.
The firm plans a rights issue to raise 2.5 billion rupees to expand in Sri Lanka and overseas.