The company, which was stung by criticism about its track record in exploration and project development from hostile bidders Peabody Energy and ArcelorMittal, said it had already spent $53 million on exploration and project evaluation that included underground mines over the past five years.

“A number of the undeveloped tenements are expected to contribute to Macarthur’s attributable saleable production beyond 2014,” the company said.

“Contracts are in place for environmental studies to support eight of these projects.”

Macarthur, which has 259 million tonnes in JORC-compliant reserves and 2.3 billion tonnes in resources, has a $60 million budget for exploration and evaluation in 2012.

“Further substantial exploration is targeted beyond financial year 2012 on a number of tenements that Macarthur believes have significant potential, in addition to continuing exploration on existing reported tenements,” the company said.

Macarthur chairman Keith DeLacy reiterated that shareholders should take no action in regards to the $4.7 billion takeover offer by the Peabody-ArcelorMittal bidding vehicle, PEAMCoal.

“Having reviewed the document thoroughly since it was lodged, Macarthur engaged with PEAMCoal to seek the removal of a number of gratuitous and potentially misleading statements in that document,” he said.

“PEAMCoal agreed to make certain changes to the bidder’s statement [although they refused to make others] and to issue a replacement bidder’s statement with a small number of deficiencies corrected.

“Your directors will provide further information in relation to remaining concerns with the bidder’s statement in Macarthur’s target’s statement.

“Importantly, Macarthur did not consider it in shareholders’ interests to seek to delay the dispatch of the replacement bidder’s statement.”

PEAMCoal is expected to dispatch its replacement bidder’s statement to Macarthur shareholders on or around August 18, 2011.

Macarthur expects to dispatch its target’s statement to shareholders by late August or early September 2011.

“The target’s statement will include your directors’ formal recommendation in relation to the PEAMCoal offer, explain a number of the remaining deficiencies identified in PEAMCoal’s bidder’s statement and provide further detail in relation to these issues,” DeLacy said.