Following this, Channel 4 said it would be reviewing its own investment in the station.
A Channel 4 spokesperson said: "As UBC have managed and operated this service for several years this decision will have a significant impact on the station and Channel 4 must review its own position as a result".
Oneword is one of the stations on the national digital radio multiplex and its latest Rajar audience figures give it a small weekly reach of 138,000 listeners. It is a speech station focused heavily on literature.
UBC's majority partner Channel 4 spent £1m to buy 51% of the station from UBC in April 2005, when it had 112,000 listeners.
This led to Channel 4 extending its involvement with the radio sector by assembling a consortium, which successfully bid to run the second national digital radio multiplex.
Channel 4 will create three of its own stations to broadcast on the multiplex.
UBC has reduced its involvement in running radio stations recently in favour of investing in its production, commercial and music download divisions.