Ostrom joined the DIY retailer in May last year after a decade working for directory enquiries services 118 118.
Following Ostrom's departure, B&Q has transferred corporate comms responsibility to a new post, head of comms, although it is not clear whether the new role has been filled yet.
During his time at B&Q Ostrom was responsible for integrating social media within customer relations, supporting management comms throughout a leadership change, and creative consumer PR output including the newsjacking of the premiere of Fifty Shades of Grey.
B&Q handed its press office and PR campaign work to Good Relations last year.
