Manager Lee Richardson has left Chesterfield after the club decided not to renew his contract.Richardson, 40, had been the Spireites' boss since taking over at Saltergate from Roy McFarland in April 2007. [LNB]He was unable to stop the club being relegated to League Two, and has failed to lead the team to promotion during the past two seasons. [LNB]They missed out on the play-offs by six points, despite the goals of League Two's joint-top goalscorer Jack Lester. [LNB]Richardson told BBC Radio Sheffield: " It's disappointing in some senses of course, but it's not a complete surprise to me. [LNB][LNB] [LNB][LNB] emp_load.getEmpEmbeddedParams("emp_8036649");"We've had tough times over the two years that I've been manager in terms of pressure on the chairman and board to make a change, in the midst of what I think are two decent seasons. [LNB]"The world has not ended, I've got three wonderful kids and a lovely wife, so I'm disappointed but life goes on. I've gained form the experience." [LNB]Chesterfield chairman Barry Hubbard told BBC Radio Sheffield: "I'm very sorry that he's gone because I think he's done well at Chesterfield. [LNB][LNB] [LNB][LNB] emp_load.getEmpEmbeddedParams("emp_8036698");"He's had some bad luck, he's had some good luck. But some of the players he's signed, I don't think have come up to the expectations he had for them." [LNB]Talking about Richardson's successor, Hubbard added: "We haven't got any candidates and we welcome all applications. We haven't got anybody in mind at all."