Liverpool have signed French teenager David Ngog from Paris Saint-Germain, the Premier League side announced on Thursday. The 19-year-old, who arrived for an undisclosed fee, has penned a four-year deal with the Reds. Ngog, who is cousin of French defender Jean-Alain Boumsong, put in some impressive displays for PSG last term. He becomes Rafael Benitez's fourth signing in the close season following the arrival of Andrea Dossena, Diego Cavalieri and Philipp Degen. Liverpool are reportedly looking to sign another striker with the likes of Robbie Keane, Samuel Eto'o and David Villa linked with moves to the Anfield Road.