Veteran internal comms specialist Mark Darby joins from Visa Europe, where he was head of internal comms. Before his role at Visa, Darby also held positions at Vodafone and Ericsson,

The move comes weeks after the ADIA brought in Euart Glendinning, former head of corporate comms at Morgan Stanley, as global head of corporate comms and public affairs.

Glendinning said Darby had an 'established track record in both internal comms and human resources', and added that the move underlined the ADIA's investment in comms.

Darby joins as head of internal comms, reporting to Glendinning.

The ADIA has more than £400m worth of investments and has been working to improve its global offering. Earlier this year, it called in Burson-Marsteller to co-ordinate comms.

Reports in the US over the past month have referred to the ADIA's 'buying binge' as the fund has grabbed stakes in a swathe of well-known businesses. In recent years, fuelled by rising oil prices, the authority has used its burgeoning wealth to take a £3bn-plus stake in Citigroup.

It has also used its separate investing arm, Mubadala Development Company, to buy into Ferrari and private equity outfit the Carlyle Group.