ISS said the reintroduction of a large discretionary cash bonus in Dimon's pay mix without a compelling rationale had weakened the performance-basis of his pay.

JPMorgan paid Dimon a cash incentive bonus of $7.4 million in 2014, his first bonus in three years. Dimon's total pay package for the year was $20 million, unchanged from last year.

ISS said Dimon's pay over the last three years "outranked" the company's total shareholder returns during the period.

Glass Lewis said its analysis indicated that JPMorgan was "deficient in aligning pay with performance."

JPMorgan's shareholders are scheduled to vote on the bank's executive pay in a non-binding motion at its annual meeting on May 19. Shareholders will also vote on whether Dimon should continue as the chairman.

Both ISS and Glass Lewis said that the bank needed to designate an independent chairman.

"Shareholders would benefit from the strongest form of independent board oversight which an independent chairman could provide," ISS said in its report.

Proxy advisers guide big shareholders such as mutual funds on how to vote in corporate elections.

Glass Lewis gave JPMorgan an "F" grade on pay-for-performance policies, lower than the "D" it gave the bank a year earlier.

(Reporting by Neha Dimri and Amrutha Gayathri in Bengaluru; Editing by Kirti Pandey and Saumyadeb Chakrabarty)