The voluntary code, which was launched in May by the Scheme Advisory Board (SAB), now has 15 signatories committed to sending cost and charge data in a standardised format to LGPS clients.
RLAM manages some £3.6bn of assets for around 50 local authorities, comprising 14 LGPS funds and 36 local authority treasury clients.
Chief executive Andrew Carter said: "We have invested for the LGPS since 1991 and are pleased to be able to provide them with more information to base their investment decisions on."
It follows Local Pensions Partnership Investments, and Pyrford International, which also signed up to the code over the last month.
Baillie Gifford was the first manager to commit to the code, signing in June, and other major asset managers have followed suit including Legal & General Investment Management, Fidelity International, and Investec Asset Management.
The Investment Association (IA) has proposed a very similar version of the LGPS' disclosure model for its code for the wider investment management industry, and consulted on it in spring. It is expected to report back on its findings later this autumn.
The Financial Conduct Authority (FCA) has also launched a working group to look at cost and charges disclosure, last month appointing Dr Chris Sier, who developed the data collection spreadsheet underpinning the LGPS' code, as chair.
The working group will comprise industry and investor representatives, who will seek to agree a standardised disclosure template building on the work already done by the LGPS and the IA.
Article click here