Narrabri’s coal resource was increased to 854.6 million tonnes, reflecting recent drilling results and the potential to recover the full seam with longwall top coal caving rather than only the lower 4.2m section.

Overall, marketable reserves increased by 16% to 322.7Mt while the total resource jumped 56% to 1.19 billion tonnes.

Measured and indicated coal resources have increased by 39% to 731.2Mt , an increase of 206.5Mt.

Included in the new resources and reserves is the East Bluevale open cut resources on CL316 as part of the Bluevale project and an initial open cut reserve at Bluevale.

An initial underground reserve for the Block 7 area, south of the former Gunnedah/Blackjack Colliery, and an initial underground reserve for the Tarrawona mine to extract coal from the lower Northam and Tarrawonga seams below the current open cut are included.

An initial resource estimate at Arthurs Seat in the Ashford Basin north of Inverell was also incorporated.

Whitehaven closed down 2.29% yesterday at $A5.12.