(Updates with cancellation of notice.)
LONDON, Nov 7 (Reuters) - Britain's National Grid cancelled a notice to back-up power suppliers that they might be called upon on Monday after supply forecasts improved.
The company said earlier that power supply margins could be close to dipping below adequate levels during the peak demand period in the late afternoon.
The automated alert was cancelled three hours later when updated forecasts showed a comfortable supply margin had been restored.
Last month, National Grid said Britain's electricity supply would be tight this winter, but there would be enough power to meet demand due to emergency back-up capacity it procured last year.
It forecast the surplus power margin to be 6.6 percent this winter.
The day-ahead UK baseload power price rose 60 percent earlier on Monday to 150 pounds per megawatt hour due to colder temperatures, less wind energy output and tight power supplies in neighbouring France due to nuclear reactor outages. (Reporting by Peter Hobson; Editing by Mark Potter)