Shares in Ausdrill were firmer after the drilling contractor posted a 50 per cent jump in first-half profit to a record $54.6 million and lifted its interim dividend by one cent to 6.5 cents fully franked.

The result was achieved on revenue of $511.7 million, up 23 per cent.

The company attributed the strong result to continued strength of the resources sector.

Ausdrill managing director Ron Sayers said the company's strategy of building a broad portfolio of services to offer its customers had placed it in an ideal position to benefit from the strength of the resources sector, both in Australia and overseas.

"Africa in particular is becoming increasingly important for Ausdrill, with strong growth delivered by our African contract mining services business," he said.

Mr Sayers said the company expected its second half performance to be similar to that of the first half, subject to no adverse weather conditions and foreign exchange movements.

"The resource industry is expected to remain exceptionally strong over the medium term in Australia and Africa and as a consequence Ausdrill remains very well placed for continued growth," he said.