The Swiss Post Office is to lose its monopoly from 2004, when other companies will be allowed to deliver parcels.
Two years later, competition will be extended to letters weighing over 100 grams, following a government decision to gradually open up the market to competition.
On Tuesday, the Swiss communications minister, Moritz Leuenberger, said liberalisation measures would take into account the specific needs of regions and the Post Office's social responsibility as an employer.
Speaking during a three-day conference of the Universal Postal Union, Leuenberger said the success of such reforms was dependent on the approval of both the general public and the Post Office's customers.
However, both the public and unions have responded with scepticism to the measures. Last week's announcement that 2,500 jobs would go at the Post Office sparked outrage, and triggered protests among postal workers.
Onslaught of competition
Samuel König, spokesman for the Union of Communications, said the Post Office is not yet ready for the onslaught of competition, which could drive its numbers further into the red, particularly in the parcels sector.
König also voiced concern that the public could suffer as a result of liberalisation. He said the pursuit of higher margins could lead the Post Office to favour its more lucrative corporate clients, with public services suffering as a result.
Conditions for postal workers could also deteriorate, with the scrapping of a collective working contract and the prospect of job losses as part of cost cutting measures, König says.
But Claude Defoundoux, UPU's head of strategic planning, has welcomed the government measures. Liberalisation was an inevitable step, he said, which many other countries were also taking.
The former head of the Post Office, Jean Noel Rey, has also endorsed the move, saying that liberalisation abroad had not had a negative impact.
"In Sweden, the market's been liberalised for a number of years, and the quality of service has remained high," he says.
Meanwhile, the Swiss Post Office has itself already taken advantage of liberalised markets abroad, with offices in New York and in Italy. Its overseas operations accounting for around ten per cent of revenues.
swissinfo, Doris Lucini