Former Manchester United and Nottingham Forest striker Sheringham has been appointed as the new manager of League Two outfit Stevenage.
The 49-year-old has been working as the attacking coach at West Ham for the past year, and he will now step into the first managerial job of his career.
Sullivan is happy to see Sheringham take such a big step and has hailed his work at the Hammers this season.
“We appointed Teddy as our new attacking coach last summer with a view to improving our forward play, and I must say he took to the part-time role with real enthusiasm and commitment,” the 66-year-old wrote on West Ham’s official website.
“With the likes of Diafra Sakho and Enner Valencia joining us and working regularly with a man of Teddy’s calibre, we know he will have helped improve their game.
“While we are disappointed to be losing Teddy’s services, we are happy to have played a part in developing his coaching skills and will be watching closely as he embarks on his managerial career at Stevenage.”
Sheringham will replace the outgoing Graham Westley, who led Stevenage to the League Two playoffs this campaign.
The Boro, who finished sixth in the ‘regular’ season, failed to get the better of Southend United in the playoff semi-finals.
Meanwhile, West Ham are currently 11th in the Premier League table with 47 points from 37 matches and are can still finish 10th.
The Hammers will take on relegation-threatened Newcastle United away from home at St. James’ Park in their final game of the season on Sunday.