Leighton Holdings has appointed Ernst & Young as an external consultant to review its continuous disclosure practices after being fined $300,000 by the Australian Securities and Investments Commission earlier this year.

As well as the fine, which was implemented in March for failing to advise investors of write-downs sooner, the regulator required Leighton to retain an external consultant to review and monitor its disclosure practices for three years.

It also warned the contractor it could take further action against it - including criminal charges - if it does not disclose material information faster in the future.

ASIC's increased scrutiny of Leighton was a factor in the company's decision to take another $254 million of write-downs in March when it flagged delays in the completion of its two key projects, Airport Link and the Victorian desalination plant.

ASIC began investigating Leighton after it took a $907 million group earnings write-down in April 2011. The penalty for not revealing the projects' financial problems - as well as those of its Middle Eastern joint venture Al Habtoor - is the most severe issued by ASIC to date for alleged continuous disclosure breaches

The last time ASIC required a company to hire an external consultant was in late 2010, when it fined Nufarm for disclosure breaches, but the chemicals manufacturer was not subjected to an ongoing audit. Leighton has not admitted to breaking any disclosure rules.

(a) What is the CDR under the ASX Listing Rule 3.1? What is its main purpose? In what ways is CDR different to quarterly reporting in terms of its advantages and disadvantages?

(b) Since the transition to IFRS in 2005, continuous disclosure has become more relevant to investors. Discuss why this is the case, with a specific reference to the Leighton case.