Revenues were down 20 percent to VND12 trillion ($519 million).
In February the company had said its revenue target for the full year was VND33.2 trillion, but in April warned it might only meet 80 percent of the target due to the Covid-19 pandemic, which has caused sales to plummet.
MobiFone had an asset of VND30.9 trillion ($1.34 billion) by the end of June, marginally down year-on-year.
It is among 91 state-owned companies that the government is seeking to privatize this year.