Penta, a fast-growing stakeholder solutions firm backed by private equity, has acquired public relations and communications firm Hume Brophy in a deal estimated to value the Irish-founded business at between $25 million and $30 million. Founded in 2005 by John Hume and Eoin Brophy, Hume Brophy has offices in Dublin, Brussels, Frankfurt, Hong Kong, London, Paris, and Singapore. It advises some of the world’s biggest agri-food, transport, energy, and financial services companies.  John Hume’s father, the late John Hume Sr, won the Nobel peace prize in 1998 for his work on the Northern Ireland peace process. Hume Jr was previously…