OIL services giant Wood Group has seen its stock upgraded by analysts at Investec.

It follows a recent capital markets day held by the Aberdeen business to explain more about its largest operating unit, PSN.

PSN is a major provider of brownfield services, mainly upgrading or repairing existing infrastructure, in the oil and gas and US shale industries.

Investec said prospects for PSN look strong as its UK operations do not have any major contract renewals due in 2015 while it has enjoyed "stellar" growth in the US where it continues to look at acquisitions.

The broker was more cautious for Wood's engineering activities particularly as the oil price has been volatile.

However even after factoring in potentially lower earnings in the engineering division Investec upgraded the stock from add to buy with a target price of 825p.

Wood Group's current chief executive Bob Keiller led a management buyout of PSN from Halliburton in 2006.

Wood Group then bought PSN for around £600 million in 2011.

Mr Keiller became chief executive of Wood Group in November 2012, replacing Allister Langlands.