(Reuters) -A shareholder adviser group, Glass Lewis, expressed new concerns about UK-based money transfer company Wise's plans to change its primary listing to the U.S., just days before a shareholder meeting, and another adviser, PIRC, said that it opposed the plans.

In a statement made public on Monday, Wise's second-biggest shareholder, Skaala Investments, urged other shareholders to vote against proposals to move the company's primary listing to the U.S. from London, because the plans also included an extension to its dual share structure, which it said was "buried" in the proposals.

On Tuesday, shareholder adviser Glass Lewis updated its report in light of Skaala's statement, and added its own concerns about the proposed extension of the dual share structure, according to a copy of the report seen by Reuters.

Glass Lewis said in its report that share structures with unequal voting rights are "typically not in the best interests of common shareholders" and that it was "concerned" by the structure being extended. But, it said, the governance issue alone was not enough for it to recommend voting against Wise's U.S. move proposal overall, which it still supported.

"DISPROPORTIONATE POWER"

Skaala had said that the changes to the shareholder structure would entrench "disproportionate power in the hands of a few", including Wise's CEO.

A spokesperson for Wise said on Monday that shareholders were "overwhelmingly in favour" of the proposal and that its process was fair. Wise cited the backing of proxy advisors including ISS, Glass Lewis and PIRC, and said that the dual-class share structure is essential for the company's success.

On Wednesday, a spokesperson for PIRC said that Wise's statement was incorrect, and that it had expressed its opposition to Wise's plans in a report on July 15. PIRC's report recommends voting against the proposals, on the grounds that the move "raises concerns about a reduced commitment to UK corporate governance standards."

"UK listing regime offers strong shareholder protections, disclosure requirements, and board accountability. Relocating to jurisdictions with less stringent oversight may weaken these safeguards," said PIRC's report, which was seen by Reuters.

A spokesperson for Wise said that the company only became aware of PIRC's opposition on Wednesday, and that it maintains that shareholders are still "overwhelmingly in favour" of the plans. ISS did not immediately respond to a request for comment.

Shareholders are voting on the issue ahead of a meeting on Monday 28 July.