Iraq is planning to hold a fifth licensing auction for exploration blocks by the end of this year or at the beginning of 2013 after its last round failed to attract many companies, a top energy advisor to the Iraqi prime minister said Monday.

Thamir Ghadhban said the Iraqi oil ministry is expected to improve the contracting terms for the new bidding round.

Only three exploration blocks were awarded out of 12 offered last month to international oil firms. Many of the companies particularly the majors didn't take part in that bidding round because of the Iraqi oil ministry's tough terms.

"The ministry will sweeten the terms for the new bidding round as it has learned the lesson from previous the bidding round," Ghadhban told reporters on the sidelines of an Iraqi energy event held by the CWC Group in
London .