Macmahon Holdings Ltd, which provides services to the mining and construction sectors, has extended its takeover offer for drilling contractor Ausdrill Ltd by three weeks.

The offer will now close on 29 September.

Macmahon said that since lifting its offer on August 20, around 14 per cent of Ausdrill shares have either been accepted into the offer or its institutional acceptance facility.

Macmahon is offering Ausdrill shareholders 1.65 Macmahon shares for each Ausdrill share.

Based on the Macmahon closing price on September 5 of $1.80, the offer implies a price for Ausdrill shares of $2.97.

Macmahon closed up one cent to $1.81, while Ausdrill fell three cents to $2.47.