(Reuters) - Proxy adviser Institutional Shareholder Services (ISS) has recommended that Google Inc's shareholders withhold votes for all three directors on the company's compensation committee, saying "mega grants" provided to the executive chairman and chief business officer were "problematic".
Google, which holds its annual meeting later on Wednesday, awarded Executive Chairman Eric Schmidt $100 million in restricted stock units last year.
It was the second time in less than three years that the company's former CEO has received an equity award of that size.
Schmidt handed the CEO reins to Google co-founder Larry Page in 2011.
Omid Kordestani, who was recently re-hired as chief business officer, received a $60 million equity award and a one-time $65 million supplemental equity award.
ISS recommended that votes be withheld for compensation committee members John Doerr, Paul Otellini and Ram Shriram.
"Although ISS has not identified any major issues regarding the structure of Google's executive compensation in past years, the magnitude of total pay provided to certain executives, paired with a lack of performance criteria and compelling rationale, raises significant concerns," ISS said in a report seen by Reuters.
(Reporting by Devika Krishna Kumar in Bengaluru; Editing by Sriraj Kalluvila)