Downer has been selling non-core businesses, aimed at restoring a share price that has dropped 15% on profit warning concerns.

Century Drilling has been up for sale for some time, according to reports, with a sale aimed at returning the book value of $105 million.

According to a Downer EDI statement on Wednesday, a non-binding agreement on terms had been reached.

“We have continued to make progress in tightening the focus of business, targeting the divestment of our foundry business, sold in March to Bradken,” said managing director of Downer EDI, Stephen Gillies.

"We continue to make further substantive progress, leading to a non-binding agreement of terms, in regard to the remaining sale of non-core resource assets, targeted to conclude in June this year.”