Public Policy Holding Co., a collection of US government affairs firms, has gone public on the London Stock Exchange’s AIM market of small and medium-sized growth companies.

The DC-based parent of Crossroads Strategies, Seven Letter, Alpine Group, Forbes Tate Partners and O’Neill & Associates floated 22.7M shares on Dec. 13 and raised more than $40M.

UK, US and European institutional investors snapped up the shares due to PPHC’s strong position in the $17.6B strategic communications market.

The level of support we have received from high quality institutional investors is a great endorsement of the strength of our business,” said CEO Stewart Hall. “Admission to AIM and the funds raised will support plans to further scale our proven business platform and we look forward to delivering on that strategy.”

PPHC firms serve more than 700 clients in the healthcare, pharma, financial services, energy, technology, telecommunications and transportation sectors.

About 75 of them are retainer-based clients. Nearly 300 of PPCH’s clients generate revenues in excess of $100K.