LONDON, June 28 Reuters Plans to ease Britain39;s company listings rules to attract more big ticket IPOs to London would roll back fundamental investor protections and weaken investors39; ability to challenge company boards, a group of pension schemes said on Wednesday.

The Financial Conduct Authority suggested in a public consultation discussion paper in May that Britain39;s twintrack listings regime could be merged into a single entry point to attract more startups. It also suggested raising the threshold for requiring shareholder approval for big transactions.

After Brexit cut off the City of London from the European Union and a decision by UK chip designer ARM to list in New York, there have been calls for a revamp of listing rules to keep Britain globally competitive in capital markets.

Railpen and nine other UK pensions schemes which oversee 300 billion pounds 379 billion in assets, said in a letter to the FCA on Wednesday that the proposals need a broad and evidence based policy discussion.

Proponents of a more relaxed UK approach to shareholder rights underestimate the extent to which investorfriendly corporate governance standards have shaped the UKs attractiveness on the world stage, said Caroline Escott, senior investment manager at Railpen, said in a statement.

Church of England Pensions Board, HSBC Bank UK Pension Scheme, and the Universities Superannuation Scheme were among the letter39;s signatories.

The Principles for Responsible Investment PRI,…