Jan. 25 (Bloomberg) -- U.K. power for delivery on the next working day rose as the network operator said a third of Britain's coal-fired electricity-generation units are halted and the cost of coal for delivery next quarter jumped.

Working day-ahead baseload power traded at 54 pounds ($107) a megawatt-hour as of 5 p.m. in London, compared with a last price yesterday of 51.75 pounds for electricity delivered today, according to prices from the broker GFI Group Inc.

There were 19 out of 59 coal-fired units off line as of 8:30 a.m. today, according to data on a Web site run by National Grid Plc, the manager of Britain's power-transmission network. Six of British Energy Group Plc's 16 nuclear reactors are also halted.

Some coal-fired plants are subject to restrictions on the number of hours they can run since tighter limits on emissions of polluting gases including sulfur dioxide were introduced on Jan. 1. Generators have been using those plants only for the most expensive periods of the day. Five plants that were off line in the morning started today, according to the grid data, while one unit at the Aberthaw plant in south Wales halted.

Power prices for the remainder of the year jumped on a surge in coal prices, as production in South Africa shut down because of power-supply shortages at mines. Coal for delivery in Europe next quarter added 7.6 percent to $123.75 a metric ton, according to prices from ICAP Plc.

Month-ahead baseload power rose 1.7 percent to 58.30 pounds a megawatt-hour, at a premium to the day-ahead price, on forecasts for cooler weather in February, which may boost demand and prompt utilities to operate more-costly generators.

Summer 2008 baseload power, covering the six months from April, added 2.9 percent to 52.70 pounds a megawatt-hour. The following six months also gained 2.9 percent to 57.60 pounds a megawatt hour.

Baseload electricity is delivered around the clock.

To contact the reporter on this story: Paul Dobson in London at pdobson2@bloomberg.net

Last Updated: January 25, 2008 12:22 EST