Despite a continuing insider trading investigation, the pending takeover of Australia's Sundance Resources Ltd. by Hanlong Mining of China is almost as good as a done deal, lacking only signatures.

Hanlong Monday raised its bid to purchase Sundance by 14 per cent to $1.7 billion from its earlier $1.4 billion offer to secure its takeover position of the iron ore mining company.

Sundance is currently in a trading halt pending a formal announcement of the acquisition.

The increased purchase take by Hanlong and Sundance's trading halt effectively defies the investigation the Australian Securities and Investments Commission last month.

"They are in the advanced stage of negotiations ... that certainly has not slowed down the process," Reuters sources said, stressing the probe would not affect talks between the two companies.

The ASIC launched an investigation last month involving five senior executives of Hanlong upon allegations of extreme profitable trades in Sundance's shares. The ASIC froze the assets of the executives and imposed travel bans as well as it launched the inquiry. Apart from the Sundance deal, ASIC is also looking at Hanlong's planned takeover of Bannerman Resources Ltd. that values the miner at A$143.4 million. Bannerman is developing a uranium project in Namibia.

The Hanlong investigation is a high-stakes case for the Australian regulator, which has yet to produce a successful insider trading prosecution.

Hanlong's latest bid offer raised Sundance's value at more than $1.5 billion, after the Chinese firm agreed to hike its proposal to 57 cents per share from the earlier 50 cents per share bid made in July.

Should the Australian miner accept the updated offer, the deal gives the Chinese company control of a major iron ore mine in Africa. Sundance is already owned 18.6 percent by Hanlong.

Sundance on Monday filed for an immediate trading halt of its securities until trading opens again on Wednesday.

"The reason for the request is to provide an update regarding the proposal from Hanlong Mining Limited to enter into a scheme of arrangement to acquire 100 per cent of the issued capital of Sundance Resources Ltd," Sundance said in a statement.