The brewery, which is in Cockermouth, was acquired by Marston’s in 2005 when plans were put in place to further invest in the site.
CMBC’s Paul Davies said the company was “incredibly proud” of the brewery team and it will prioritise support for the staff as the consultation period is entered.
He added: “We understand the great affection the local community has for the brewery and its place as part of the UK’s brewing heritage.
“We are pleased to continue brewing Cumberland Cask by moving production to the historic Marston’s Brewery in Burton, which as a fantastic track record of producing traditional cask beers.”
However, this move was criticised by the Campaign for Real Ale (CAMRA), which called for the brewing business to consider creating Cumberland still in Cumbria, rather than Burton.
CAMRA chairman Nik Antona said: “Sadly, this is now an expected consequence of global brewers entering and consolidating the UK beer market – shutting distinctive regional brands and eroding the nation’s brewing history.”
CMBC’s Davies outlined the reasons behind the closure of the Cumbrian-based brewery, which first opened in the 1800s.
He added: “Jennings has operated below capacity for a number of years and has seen a significant decline in volumes, the impact of which has been made more significant by the pandemic.
“Over the course of the past year, we have carefully considered all options for the brewer and have reached the extremely difficult decision to close the brewery.
“We understand this news will be very difficult for our team at Jennings and disappointing to many other colleagues, consumers and customers.
“But with the economic headwinds impacting our industry, we must continue to make the difficult choices we believe are needed to ensure CMBC is well placed to navigate the unprecedented external challenges we are facing and ensure we are able to grow and sustain our position as a leading business in the brewing industry.”
CAMRA urged the brewer to retain the venue as it is and produce beer instead of it closing for good.
Antona said: “The announcement from CMBC that it intends to shut and sell the Jennings Brewery site in Cockermouth is a devastating blow for the area’s brewing heritage.
“It is vital CMBC does everything it can to keep the site as a working brewery rather than having this part of our history lost to conversion to housing or another use.
At the end of last year (December), CMBC announced it had closed London Fields Brewery, shutting the taproom and ceasing brewing as it looked to sell the site and brand.