* Outage website shows one 490-MW unit offline
* Fire crews at blaze at coal plant in West Yorkshire (Adds details)
LONDON, July 31 (Reuters) - A fire broke out at Britain's Ferrybridge coal-fired power plant in West Yorkshire on Thursday, owner and operator SSE said, with no injuries reported but one generation unit going offline.
Two units generate electricity at the plant, known as Ferrybridge C, which with a combined capacity of nearly 1 gigawatt can power at least 700,000 homes.
"All personnel have been accounted for and no injuries have been reported at this stage," a company spokesman said. Fire crews were at the scene of the blaze, which was reported at around 2 p.m. local time (1300 GMT), he added.
One of the units at Ferrybridge, with a capacity of 490 megawatts, went offline at 3:48 p.m. and was expected to return to service on Aug. 4 at 5 p.m., the company's website showed. (http://remit.sse.com/)
The West Yorkshire Fire and Rescue Service said 10 fire engines were at the scene and that the third floor of a four-storey building was involved in the blaze.
"It is too early to give any more information regarding this incident; however, we will issue a further statement when more details become available," the SSE spokesman said. (Reporting by Nina Chestney; Editing by Dale Hudson)