Macmahon Holdings (ASX:MAH) executed a share purchase agreement to acquire 100% of the engineering and project delivery business, Aspect Engineering Solutions, and associated subsidiaries, according to a Friday Australian bourse filing.

The consideration will be paid over five years, including an initial upfront cash payment of AU$30 million on completion, yearly retention payments of AU$6 million per year for five years totalling AU$30 million, and earn-out payments of between AU$15 million and AU$30 million dollars over three to five years.

Macmahon may, at its discretion, elect to pay future retention payments and earn-out payments in the form of Macmahon shares rather than cash.

Aspect's executive management will remain with the business, as will its workforce.