Activist funds such as Crystal Amber search for companies they believe are undervalued, take a position in the stock and then agitate for change at board level to try and increase the value of the firm.

Faced with a challenging market and economic outlook after Britain's late-June referendum on European membership, Crystal Amber said, as it reported full-year results, that it believed company management may be more open to engaging as a result.

"We believe the fallout from Brexit has created a number of activist opportunities as companies are forced to adjust to inevitable changes," it said.

The activist manager, which has 151 million pounds in assets, said its top-10 positions include Britain's largest listed residential property owner Grainger and oil exploration company Hurricane Energy .

Its most profitable investment for the year was a 5.7 percent stake in James Bond filmmaker Pinewood Group, which earned Crystal Amber 6.1 million pounds after a takeover deal by Aermont Capital.

Some of Crystal Amber's investments, such as in STV Group and Northgate , lost money for the hedge fund over the year.

(Reporting by Maiya Keidan, editing by Louise Heavens)

By Maiya Keidan