West Brom have sacked chairman John Williams and chief executive Martin Goodman as owner Guochuan Lai responded to the club's poor run of form.
A club statement said the changes "follow Albion's poor results".
Both Williams and Goodman "have been placed on garden leave with immediate effect", with Mark Jenkins becoming the club's new chief executive.
West Brom have been in English football's top flight for eight successive seasons but have only picked up 20 points from 27 matches and are seven points behind 17th-placed Huddersfield Town.
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Albion sacked Tony Pulis as manager on 20 November.His replacement Alan Pardew has only won one league game out of 13 since taking over.
A club spokesman said:"We would like to thank John and Martin for all their efforts since their appointments and wish them well for the future."
Jenkins had previously been chief executive of the club for 10 years before leaving in November 2016, with Goodman taking over from him.
However, Jenkins had recently returned to the Hawthorns as a director of WBA Holdings, the club's controlling company, and is now back in his former role.
He said:"There is much to do but for now the focus must solely be on the remaining games of this season."
West Brom are next in action on Saturday, 17 February with a home tie against Southampton in the fifth round of the FA Cup before hosting Huddersfield in the Premier League on Saturday, 24 February.
Who is John Williams?
Williams carried out the roles of both chairman and chief executive in a 14-year spell at Blackburn Rovers from 1997 to 2011 but he left the club following the takeover of the controversial Venky's group.
In 2014 he was named chairman of the referees' body, the Professional Game Match Officials, before taking over at West Brom at the recommendation of outgoing owner Jeremy Peace....