Patriot said the estimated time for the longwall to ramp up to full production was a conservative approach to remedying the situation and ensuring the safety of its workers.
The company believes the condition is temporary and that Federal will resume its normal production rate in the second quarter.
The lower production at the Federal mine will impact first-quarter 2008 earnings, but the company was unable to provide a guidance.
It said improving markets and other favourable circumstances that were not included in its full-year guidance would offset some of the lost production.
Patriot holds 10 company-operated mines and numerous contractor-operated mines in Appalachia and the Illinois Basin.