A "significant investment" at the base in Siskin Drive to install new packing equipment means a reduction in staff, Brian Waltham, from Walkers, said.
It will substantially improve and upgrade the site, he said.
A spokesman for Unite said it would have more information at the end of the year once consultation with the Leicester-based crisp giant ends.
In a statement, Mr Waltham, site leader in Coventry, said it continually reviewed its operations there.
"Having looked extensively at our Coventry site, we are planning a significant investment to install new state-of-the-art packing equipment. This move will substantially improve and upgrade the site and ensure we have the capacity to support the long-term growth of the Walkers business in the UK.
"Unfortunately, up to 75 roles are at risk as result of this investment but we are working hard to reduce the number of employee redundancies through the consultation process.
"The decision to make these changes has been very carefully considered and subject to consultation with our union."
More than 70 jobs at a Walkers crisps plant in Coventry are under threat, the firm says.