CIMIC has stepped up its acquisition spree by making a $243 million full takeover play for mining services group Sedgman.

Sedgman has asked shareholders not to take any action for now while its board considers the offer made by its largest shareholder.

Sedgman shares surged by more than a third, closing 28 cents higher at $1.07.

CIMIC made an unconditional offer to buy the 63.01 per cent of Sedgman shares it does not already own, at a price of $1.07 each. The offer implied a 35 per cent premium to Sedgman’s closing price of 79 cents on Tuesday.

“As the offer is specified to be unconditional, CIMIC will not be able to withdraw. Therefore, there is no need for shareholders to take any action at this time,” Sedgman’s directors, other than the CIMIC nominee on the board, said in a statementCIMIC in $243m Takeover of Sedgman.

Sedgman said its board had formed a separate panel to consider the offer, and had also appointed Citi and Norton Rose Fulbright as advisers.

The company also is in the process of appointing an independent expert to evaluate the offer.

CIMIC’s bid comes just weeks after it launched a $119 million takeover offer for residential property developer Devine and voted against executive remuneration proposals at mining services firm Macmahon Holdings.

The construction giant, formerly called Leighton Holdings before it was acquired by Spanish infrastructure group ACS in 2015, has been looking to further strengthen its hold in the Australian market.

CIMIC has been a long-time strategic investor in Brisbane-based Sedgman, which offers construction and maintenance services to the global mining industry.

It currently holds 36.99 per cent in the Australian company, while unit Theiss also has several joint ventures with Sedgman.

“CIMIC is seeking to increase its shareholding in Sedgman to a level where it can better support the future direction of Sedgman,” it said in a statement to the ASX.

It said it planned to restructure Sedgman’s board and review the company’s capital management policies.

In November, CIMIC surprised Sedgman’s board by voting against most resolutions at the company’s annual general meeting, resulting in several of its directors having to step down.

At the time, it had demanded more representation on the company’s board and asked that Sedgman’s founder directors be removed.