Perth-based CopperCo - which mines copper at the Lady Annie project in Queensland - today said it had appointed Shaun Fraser, Simon Read and James Thackray of McGrath Nicol as voluntary administrators of the company.

CopperCo called a trading halt on November 20 over the "potential financing transactions" and said these transactions - which would provide financial support through new equity and debt facilities ¬- were progressing.

However in a statement today, the company said it was advised on November 25 that the transactions would not take place.

"Having considered all relevant matters, the board concluded that the appointment of administrators was appropriate in the circumstances," CopperCo said.

The company also appointed Darren Weaver, Andrew Saker and Peter Geroff of Ferrier Hodgson as receivers and managers.

The suspension of trading in CopperCo's shares will continue following today's announcement.

In the last quarter, CopperCo sold just under 4000 tonnes of copper from the operation for a net revenue of $26.2 million, however since the start of July spot copper prices have declined from $US8900 per tonne to current levels of $3698/t.

Cash costs at Lady Annie were $US1.08 per pound during the last quarter, down 6% from $US1.15 in the previous period.

CopperCo said in its last quarterly report it had "copper price protection" in place and the declining Aussie dollar had also shielded it from the full impact of the fall.

This year the company also merged with mining investment company Mineral Securities, which had a number of development projects on its books.

The news comes after a tough October and November for the copper sector, with Matrix Metals and Tamaya Resources separately calling in administrators over the space of a fortnight.

Shares in CopperCo have fallen from a high of $1.24 in 2007 to 5c when trading was suspended last Thursday.