The FTSE Group has launched a consultation on raising the minimum free float requirements for incorporated companies in its indices, and could also look at creating a new set of indices requiring higher corporate governance standards.

Under current rules, companies can be included in the FTSE UK Index Series if they at least 15 percent of shares free to be traded, although firms with a market capitalisation of more than $5 billion (3 billion pound) can have a free float as low as 5 percent.

In respect of the UK Index Series, FTSE has received a number of requests to raise the minimum free float requirement for a company to 25 percent, the group said on Tuesday.

The UK Listing Authority (UKLA) already requires firms seeking a premium listing to have a 25 percent free float, but has on occasion waved this requirement, meaning companies with lower free floats have made it in to the FTSE indices.

Those affected by a possible change would include precious metals miner Fresnillo Plc , India-focussed Essar Energy , miner ENRC and Ukrainian iron ore producer Ferrexpo , FTSE said.

If a change is made following the consultation, which runs until November 25, these companies will be given time to increase their free float.

FTSE, which is jointly owned by The Financial Times and London Stock Exchange , also said it would also consult on whether exceptions should be granted in cases where the UKLA waves its minimum.

The consultation also includes a proposal to set up a new index series which would require companies to meet minimum governance criteria.

FTSE is considering the creation of a new set of UK indices, running alongside the current series, which would impose a higher standard of corporate governance, the consultation said.

Corporate brokers, traders, investment managers and pension funds are among those invited to take part in the consultation.

(Editing by Erica Billingham)