The Post Office has backtracked on plans to radically slim down its operations. Some 2,400 jobs will still be cut in an overhaul of its sorting centres which will be reduced from 18 to nine.
The measures are expected to save SFr170 million ($133 million) annually as Swiss Post gears up for liberalisation.
Last October, Swiss Post announced plans to cut 2,800 jobs and drastically reduce the number of sorting centres from 18 to just three.
But on Tuesday, officials said they would consolidate operations into three principal mail sorting centres, and keep six secondary units going.
The initial measures - deemed necessary to compete in a liberalised market - were met with stiff resistance from workers and unions.
Trade unions welcomed the scaled-back restructuring programme, saying it was the best of a bad deal.
The communications minister, Moritz Leuenberger, also expressed his relief, saying the revised plans were a good compromise solution, taking into account social and economic factors.
The three new sorting centres will be established in the French-speaking region near Lausanne and Yverdon. Two others will be in the German-speaking region: one in central Switzerland near Solothurn; the other in Zurich.
The six smaller centres are in Geneva, Basel, Bern, Lucerne, St Gallen and Ticino.
The first new centre is due to open in 2006 and the others are expected to be in operation from 2008.
Some 3,130 workers will be affected by the changes.
"The measures are based on evaluations by Swiss Post, which forecasts a reduction in the volume of letters of about ten per cent," Swiss Post said in a statement.
"By modernising the courier centres, Swiss Post hopes to assure its long-term viability and key jobs."
Swiss Post admitted that the revised restructuring plan would save less money - SFr170 million instead of SFr222 million per year. However, it said the plan still allowed "the yellow giant" to remain competitive.
The Swiss Post Office will lose its monopoly from 2004, when other companies will be allowed to deliver parcels, following the government's decision to gradually open up the market to competition.
Two years later, competition will be extended to letters weighing over 100 grams.
swissinfo with agencies
Swiss Post recorded a profit of SFr204 million ($158.84 million) in 2002.
Swiss Post is Switzerland's second-largest employer, with 55,730 staff.
The Post delivers some 17 million letters and newspapers and 500,000 parcels a day.
It has a network of 2,921 post offices, with 18 letter centres and four parcel centres.