Former nuclear business AEA Technology has sold its engineering software arm for £67.5m.

US company Aspen Technology has bought the Hyprotech business, which has been up for sale since last June. It sells simulation software to petroleum refineries.

The deal boosted shares in AEA Technology, which last June announced 75 voluntary redundancies at its Harwell headquarters.

AEA Technology, the privatised wing of Britain's atomic energy authority, has already sold two nuclear business after poor financial results.