public class RepeaterEx:Repeater
{

    
    [PersistenceMode(PersistenceMode.InnerProperty), TemplateContainer(typeof(TemplateControl))]
    public ITemplate PagerTemplate{get;set}

     protected override void OnLoad(EventArgs e)
        {
            if (PagerTemplate != null)
               PagerTemplate.InstantiateIn(this);

            base.OnLoad(e);
            
        }

protected override void OnInit(EventArgs e)
        {

            this.PagerTemplate = Page.LoadTemplate("~/Pager.ascx");
   
            base.OnInit(e);
        }

}