Silver Lake said this month it was buying the real estate portal, which also operates the PrimeLocation website and comparison service uSwitch, for 2.2 billion pounds ($2.94 billion).
"We are excited about the prospect of working with Silver Lake and the opportunity this offers to our employees, consumers and partners," founder and CEO Alex Chesterman said on Wednesday.
Chesterman, who launched the Zoopla website in 2008, said he would remain with the business after Silver Lake's 4.90 pound per share cash buyout which will be discussed at a shareholder meeting due to be held on June 18.
Chesterman has around a 1 percent stake in ZPG according to the company's statement earlier this month on the Silver Lake deal.
Chesterman said since rival property website OnTheMarket dropped its "one other portal rule" earlier this year the number of agents joining ZPG had risen significantly.
OnTheMarket had previously required agents to list with only one other portal, such as Zoopla or Rightmove, with many opting for the latter.
"We've been winning back agents over the last three months at twice the rate of the three months prior to that and four times the rate of the same three months last year," Chesterman said.
OnTheMarket said earlier this month it had seen a 45 percent increase in agents to more than 8,000 listed on its portal by May 11 over the three months since it debuted on London's junior stock exchange AIM in February.
Zoopla's profit rose 33 percent to 22.4 million pounds in the six months to the end of March while revenue also rose by a third to 157 million pounds.
Listings increased by 6 percent to 982,000 whilst the number of estate agents on its sites rose by 7 percent to 15,264 branches.
($1 = 0.7490 pounds)
(Reporting by Costas Pitas; editing by Paul Sandle, Jason Neely and Jane Merriman)
By Costas Pitas