A SeaWorld penguin poses next to a NYSE trader's tablet at the launch of SeaWorld's IPO.

The Blackstone Group, the single largest shareholder in SeaWorld Entertainment, plans to further cut its stake in the water theme parks company, according to the San Diego Union-Tribune.

Blackstone, which took SeaWorld public one year ago, seeks to reduce its stake to 25 percent from 43 percent, according to a prospectus filed Monday. In December, Blackstone owned 63 percent of the company, when it sold 18 million shares.