LONDON, May 20 (Reuters) - Britain will finalise its

biggest shake-up of company listing rules in decades over the

coming weeks, regulators said on Monday, as industry officials

cautioned that the reform alone won't transform London's ability

to catch up with New York.

The Financial Conduct Authority's executive director Sarah

Pritchard said the listings changes would help boost UK growth

and competitiveness.

The changes are expected to include merging the more heavily

regulated premium segment with the less onerously regulated

standard segment, in a bid to cut red tape.

Investors would rely on more disclosures from companies

rather than on mandatory requirements that they be consulted.

"But as we know that these reforms will involve a different

balance of risk, we have sought to engage extensively across the

market, including with investors, to build as much consensus as

possible before we reach our final decisions by the summer,"

Pritchard told a City & Financial conference.

Britain has set out a welter of regulatory changes to

bolster London post-Brexit as a global financial centre, but so

far this year it has lagged New York and Europe overall in

initial public offerings (IPOs).

"Per se, I don't think the listing rules change or transform

the attraction of London as a listing venue," said Charlie

Lytle, chairman of corporate broking at Goldman Sachs ( GS ) bank,

adding that it would remove some longstanding regulatory

hurdles.

It was also unclear if the anticipated sale of the

government's remaining shares in NatWest ( NWG ) bank to retail

investors would "light a fuse or just be a one off" boost, Lytle

added.

"A series of IPOs would be very helpful," Lytle said.

Gavin Lewis, managing director and head of UK Institutional

client business at asset manager BlackRock ( BLK ), said the lack of

listings could be a symptom of Britain's "relative decline"

after falling productivity over a number of years.

Darko Hajdukovic, head of new and private markets at London

Stock Exchange Group ( LDNXF ), said Britain needs to be more agile as

rival financial centres like Singapore and Europe reform their

own rules.

"We just need to make sure that we don't think 'OK, we have

done that, job done, let's forget about it'. It's a constant

process that needs to be evolving and needs to be quicker,"

Hajdukovic said.