SpinVox had been given extra time to repay a £30m loan.
UK firm Spinvox, which converts voicemails into texts, has been bought by speech recognition company Nuance for $102.5m (£64m).
The deal is worth $66m in cash and $36.5m in stock, about a third shy of the earlier rumoured $146m price tag.
Nuance told BBC News it is too early to say what impact the deal will have on Spinvox's 230 staff.
It also declined to comment on whether Spinvox founders Christina Domecq and Daniel Doulton will remain on board.
"At the beginning of the year Spinvox was riding high as one of Britain's most promising technology companies," said BBC technology correspondent Rory Cellan-Jones.
"But the year has ended with it being sold at a knock-down price which means its investors are not likely to see much of a return."
More than $200m has been invested in the company so far and it had also been given a £30m loan.
"Nuance is likely to have been more interested in Spinvox's contracts with major telecoms firms - such as Telefonica - than in its technology," added Mr Cellan-Jones.
Spinvox investor Invesco Perpetual had confirmed in September that Spinvox was up for sale.
In recent months doubts had been cast on how effective Spinvox's speech-to-text software actually was.
The company claims to use advanced voice recognition software for its service, but the BBC found that human operators were also involved in transcribing many messages.
"Around the world, the voice-to-text market has experienced tremendous growth over the last year," said John Pollard, vice president of Nuance Voice-to-Text Services.
"With Spinvox's robust infrastructure, language support and operational experience, we will broaden the reach and capabilities of our platform."