Whittington has held a licence for over 10 years at his Hill Barn Stables base overlooking Lambourn and enjoyed notable big-race success with the likes of Arzal, Saint Calvados, Simply The Betts and Rouge Vif.
Arzal provided him with top-level success when landing Aintree's Manifesto Novices' Chase in 2016, while his only Cheltenham Festival victory came curtesy of Simply The Betts - who obliged favourite backers in the 2020 Brown Advisory & Merriebelle Stable Plate Handicap Chase.
That 2019/20 season was also Whittington's best numerically, amassing 30 winners and £455,667 in prize-money, but since then he has struggled to hit the same heights, saddling 19 and 10 winners respectively in the subsequent two campaigns and sitting on 10 for the current term.
Having combined his training commitments by undertaking pre-training services this term, Whittington has now taken the decision to focus solely on the latter aspect of his business.
"After many successful years as a licensed yard, we have decided to transition our operation at the end of the season to a yard which is focussed on pre-training services such as breaking-in, turnout, rehabilitation and sales consignment," read a statement on the handler's Twitter profile.
"An opportunity came up last summer to reintroduce some horses into pre-training, a discipline which we originally set out to do before taking out a trainer's licence in 2012.
"Within a short space of time we have brought in several new clients and demand has been such that we soon realised we needed to make a choice between the two rather than continue to operate the yard on a hybrid model.
"The decision was not taken lightly as we have such fantastic support from loyal owners. However, ultimately, we have made the choice because it is the best use of our collective skills as horsemen. It's a business model which works, and we are well positioned with fantastic facilities which are ideally suited to this alternative venture.
"We would like to thank you all for your continued support and look forward to moving into this new chapter."