NZ Post's moves to cut mail volumes and slash 2000 jobs saw independent experts raise its valuation by more than $100 million.
Yesterday Treasury released its report on its commercial businesses, which collectively employ more than 40,000 people.
With some exceptions, the overall performance of the businesses had been "mediocre" in the year to June 30.
But the report revealed a number of major increases in the value of some of them since the last time it commissioned independent experts to assess them in 2011.
This included the value of NZ Post rising by $268 million two years ago to $1.25 billion.
Treasury said about half of the gain came from NZ Post's request, which was accepted by the Government, to cut delivery frequency to as little as three days a week.
It also plans to increase the number of self-service kiosks it operates, while more of its Post Shops will be operated under contract.
In November NZ Post chairman Sir Michael Cullen said the moves would see it cut 2000 from its workforce over four years, starting next year.
Analysts at EY (previously Ernst & Young) said based on the changes the company wanted to make (which had not been confirmed when it wrote the report), the postal business of NZ Post was worth $117m.
In 2011, experts said the postal business was worth $3m at most, and could represent a liability of as much $35m, as it was likely to start making major losses as mail volumes declined.
EPMU postal organiser Joe Gallagher said the Government was clearly attempting to "squeeze every dollar" out of NZ Post, and had given company's management levers to pull to strip out costs at speed.
The EY report estimated the moves would cut costs by $30m a year.
In comparison with the struggling postal business, EY valued NZ Post's Kiwibank subsidiary at almost $1b, forecasting that it would continue to take market share from the four major Australian banks.
The Treasury report also revealed that losses at Wellington-headquartered Learning Media ballooned out to $9m last year, after the Ministry of Education opened many of its contracts to competition.
In September the Government announced that it would carry out a managed wind down of Learning Media, which produced the School Journal, because it was not financially sustainable.
Earlier this month the company was placed into receivership, amid threats of legal action from its landlord.
Overall the valuations of the Government's commercial businesses, excluding those earmarked for partial sale by the Government, rose by $550m to more than $5b.
This was despite KiwiRail being valued as a liability to the Crown of almost $600m.