The San Francisco 49ers have signed nose tackle Ian Williams to a two-year contract extension.
The deal announced by the team Monday will carry Williams through the 2015 season. He was third on the depth chart last season behind Isaac Sopoaga and Ricky Jean Francois, who are both free agents.
San Francisco signed Williams as an undrafted free agent out of Notre Dame in July 2011. He has seven tackles in four games over the past two seasons.
The 23-year-old Williams is a native of Altamonte Springs, Fla. He had 161 tackles, two interceptions and 1½ sacks in 45 games for the Fighting Irish.