Computer maker Hewlett Packard is planning to move all its Scottish employees to its main plant in Erskine, Renfrewshire.
The move will mean the closure of its site at Inchinnan near Glasgow airport.
The electronics giant is also proposing to outsource 250 jobs in Erskine to the employment agency, Manpower.
The changes are due to take place early next year.
Different working patterns
The Scottish National Party slammed the proposals to move staff to an employment agency.
SNP MSP for the West of Scotland, Bruce McFee, called the announcement "a severe blow".
He said: "In effect 260 people have lost their jobs with a respected company and will now be working for an employment agency.
"The proposals mean that the production workers will only keep the same terms and conditions if they adopt totally different working patterns.
"HP has made a series of these announcements in recent years. They sack full time permanent workers only for them to be rehired at a later point on a temporary contract."
In July last year, Hewlett-Packard announced 650 job losses at its plant in Erskine following its merger with Compaq.