Releasing its bidder statement today, Spanish controlled Hochtief said some roles at Leighton might be made redundant and some of the company brands, such as John Holland and Thiess, merged or dropped.

“As a result of the general review by Leighton already underway, some employees may become redundant,” Hochtief said.

“A particular focus of the review is whether the existing operating businesses of Leighton can be more efficiently structured.”

The review is expected to be completed by the end of the year.

Subject to its outcome, more management changes may be made.

Last week, Hochtief terminated the employments of both Leighton Holdings CEO Hamish Tyrwhitt and chief financial officer Peter Gregg.

They were given exit packages worth about $24 million overall.

Hochtief CEO Marcelino Fernandez Verdes will replace Tyrwhitt.

Leighton’s acceptance of the offer saw Hochtief increase its stake in the Australian company from 58.8% to up to 73.8% for a total cash consideration of about $1.2 billion.

Under the terms of the bid implementation agreement, two new Hochtief representatives have been appointed to the Leighton board and three Leighton directors are planning to resign or retire by the 2014 annual general meeting.

Leighton minority shareholders now have until May 9 at the earliest to decide whether to accept Hochtief’s offer to buy three out of every eight Leighton shares at $A22.50 per share.

The offer represents a 20.6% premium over the dividend-adjusted five-day volume weighted average price of $18.65 per share.

Leighton’s board suggest minority shareholders should accept Hochtief’s offer in the absence of a superior proposal.

“If a shareholder does not accept the offer, then that shareholder may sell all or some of their shares on market and three out of eight of these shares will be sold on a ‘cum-offer’ basis,” the Leighton board told the share market today.

“Any purchaser of those shares will be entitled to accept the offer in respect of three out of eight of those shares.”

Shareholders who accept the takeover offer will be entitled to keep or sell their remaining shares in a separate trade.

Any trades of those remaining shares will not settle until after the end of the offer.

The 2013 financial year final dividend payment will occur on April 4 for all shareholders, even to those who accepted Hochtief’s offer or sold all of their Leighton shares.

They will receive 60c per share, 50% franked.

Leighton shares dropped 4.7% to $20.36.