By Simon Jessop

LONDON (Reuters) - British asset manager M&G Investments, the fund arm of insurer Prudential <PRU.L>, is looking at expanding its operations in Dublin in the wake of a British vote to leave the European Union.

Under current rules, asset managers need an EU base to sell investment funds to continental retail investors, although the rules under which UK-based managers will access European clients after the vote have yet to be clarified.

While most of its rivals already have substantial retail operations in Dublin and Luxembourg, M&G runs a small number of funds aimed at institutional investors out of Dublin and also has a so-called 'feeder' fund, which helps collect money for retail-focused funds managed in Britain.

Around 10 percent of its 246 billion pounds ($327.30 billion) in assets is currently sold from Britain to non-UK customers, which comprises sales to continental European clients as well as those based in Asia.

The company said work was well-advanced in putting in place legal structures in Ireland and Luxembourg which would give it operational options, but that no funds or personnel were in the process of relocating.

"We've been doing a lot of planning for this ... for the last year or so, we've been working on an extension of our Ireland-domiciled funds, so our operational preparations are quite well advanced," a company spokeswoman said.

Dublin is currently the firm's preferred option although it had others and so no decision had been taken, she added, saying any final decision would depend on the outcome of talks between Britain and the EU over the terms of Brexit.

The firm would also step up its work with policy makers in London and Brussels in an effort to minimize the disruption to its customers, she said.

(Editing by Sinead Cruise and Alexandra Hudson)