MUMBAI, April 13 -- Portfolio management services (PMS) firms have asked the market regulator to widen their investment universe, as the segment struggles to keep pace with rival products, four people aware of the discussions said.

Key demands include allowing investments in unlisted markets and permission to participate as anchor investors in initial public offerings (IPO), both currently restricted for PMS structures.

Currently, only non-discretionary PMS allows up to 25% allocation to unlisted securities, such as alternative investment fund units, real estate investment trusts and infrastructure investment trusts. Discretionary PMS, which accounts for 92% of total PMS assets as of February, is not allowed to invest in unlisted securi...