By Laurence Fletcher

LONDON (Reuters) - The 1.3 billion-pound Witan investment trust has appointed three new fund firms to run part of its assets, because it believes they will be more suited to current volatile market conditions.

Witan WTAN.L, which in 2004 moved part of its assets away from fund firm Henderson Global Investors to a range of other external managers, said on Tuesday it is giving 75 million pounds to a portfolio mirroring Derek Stuart's top-performing Artemis UK Special Situations and 75 million pounds to London-based Marathon Asset Management.

This has been funded by cutting back exposure to an enhanced index portfolio run by Henderson, which now accounts for 195 million pounds of Witan's assets.

Enhanced index portfolios aim to deliver a return slightly better than that of the benchmark index.

"We'd enjoyed a pretty good run from a beta-driven strategy ... and we'd now reached a point where the world is considerably more volatile, and this is likely to continue in the short and medium-term," Witan marketing director James Budden told Reuters.

"We (also) felt after the review last year ... that there was scope to take a more alpha-driven approach."

Alpha means returns dependent on an individual manager's skill, while beta is overall market returns.

Witan has also given Paris-based Varenne Capital Partners, which takes a private equity approach to investing in quoted companies, a 30 million-pound portfolio, which has been funded out of cash.