Fund management group Henderson's board has announced an agreement for the acquisition of beleaguered asset management firm Gartmore, for an estimated £355 million.  

Shares in the group were up more than 11 per cent at 154p on 13 January, as the company says the acquisition will lead to a 'significant enhancement' of its presence, with combined assets under management of £78 billion. This will make Henderson the sixth largest fund management firm in the UK retail space.

Based on the closing price of 138.2p per Henderson share on 11 January, which was the last business day before the announcement, the acquisition values each Gartmore share at 92.1p and values the issued share capital of Gartmore at approximately £335.3 million.

Gartmore shareholders will hold approximately 22.5 per cent of the enlarged share capital of Henderson immediately following the completion of the deal. The directors of Gartmore, who have been advised by Goldman Sachs during discussions, say they consider the terms of the acquisition to be fair and reasonable and would unanimously recommend shareholders vote in favour of the acquisition.

Twelve Gartmore fund managers have said they will remain with the combined group, including Charlie Awdry and Chris Palmer from the emerging markets team and John Bennett from the European equities team. Henderson says it is still working to secure the support of further Gartmore fund managers and says the 12 it has already secured represented 84 per cent of Gartmore’s assets under management.

Completion of the acquisition will take place within the next three months, subject to Henderson and Gartmore shareholder and regulatory approval.

Andrew Formica, chief executive of Henderson Group, says: 'The acquisition of Gartmore is a great opportunity for Henderson. Gartmore has a highly complementary strategy and stable of products to that of Henderson. Its recent travails should not overshadow the fact that Gartmore is one of the best known managers in UK fund management and its assets are performing well.'

At the tail end of last year Gartmore went through a tumultuous time when its star fund manager Roger Guy and its chief investment officer Dominic Rossi announced their departure. Since it floated in 2009 at 220p, shares in Gartmore have more than halved to 100p.