Investment companies trying to choose which research houses to use in a new era of EU trading rules should be allowed to take free three-month trials with providers to help them decide, according to the UK regulator.

The Financial Conduct Authority's final policy paper on implementing the EU's revised Markets in Financial Instruments Directive states that trial periods could serve as "an acceptable minor non-monetary benefit for firms" as long as investment companies do not take trials for longer than three months, do not pay the research provider during that period, and do not return to a provider for a new trial within a year.