Cisco Systems Inc is expected to cut thousands of jobs in possibly its worst-ever round of layoffs to meet Chief Executive John Chambers' goal of slashing costs by $1 billion.

Four analysts contacted by Reuters estimated the world's largest maker of network equipment will eliminate up to 4,000 jobs in coming months, with the average forecast at 3,000. That would represent 4 per cent of Cisco's 73,000 permanent workers. It also has an undisclosed number of temporary contractors.

Cisco's previous record layoffs was set in fiscal 2002, when the company shed some 2,000 jobs, according to Canaccord Genuity analyst Paul Mansky.