The San Diego Chargers have signed left tackle Roman Oben to a two-year contract extension that will run through the 2008 season. Oben is in his second season with the Chargers. He has started all 24 regular season and postseason games since joining the club. Oben was acquired in a trade with the Tampa Bay Buccaneers for a fifth-round draft pick. For his career, Oben has started 134 of 141 regular season and postseason games.