The capital is being released through an issue of unlisted B and C shares that either pay a dividend or are bought back from shareholders, the company said.
The return is part of a £1.08bn programme of returning capital to its investors after it successfully sold its well support unit to General Electric for £1.75bn in February.
Wood Group has already released £412m through a share buyback in May, which pushed its share price up above 700p.
It said at the time that any funds not returned at that time would be disbursed through a second share placement scheme.
“This arrangement, known as a B/C Share Scheme, has been chosen as it allows shareholders, subject to applicable overseas restrictions, to choose between income, immediate capital, deferred capital or any combination of the three,” it said in a statement.
Wood Group shares closed at 638.5p on Friday.