Widnes have confirmed Paul Cullen has stepped down from his role as director of rugby.
The former Warrington coach took up the position of head coach in March 2009 with a view to prepare the club's rugby department for a Super League licence application, which they received last summer.
Cullen was replaced as head coach by Dennis Betts in November 2010 and the club have just completed their first season back in the top flight, finishing bottom.
"I have enjoyed my time at Widnes and the time is now right for me to move on," said Cullen.
"I hope I have played my part in a revolution and it is now time for the Vikings to evolve.
"I believe that my objectives have been met which were to win a trophy, win a licence, change from part-time to full-time professionalism and to deliver Super League to the supporters of the Widnes Vikings after six years in the Championship."
Club Chairman Steve O'Connor said: "On behalf of the Board, Staff, Coaches, players and fans I wish to thank Paul for all his efforts at the club.
"He has made a significant contribution to the development of our club as we made the transition into a full time Super League organisation.
"We wish him the best of luck in his future career."