It is the latest knock against an industry that had only recently won back investor favor after being shunned due to disappointing returns.
Miners who overspent on acquisitions in the 2011 gold boom have curbed premiums that led to billions in impairments when prices later crashed.
But investors say change-of-control provisions allowing for multi-million dollar executive windfalls remain commonplace.
"It's excessive and it's something that we don't like to see as shareholders," said portfolio manager Joe Foster at Van Eck Associates Corp, which holds shares in Barrick Gold Corp, Newmont Corp and other gold miners.
"These CEOs, they all have nice pay packages as it is," he said, adding that he plans to use "say on pay" proxy votes, and meetings with management, to express his view.
Teranga Gold Corp executives collectively will receive $10 million in severance pay plus $20.9 million for accelerated vesting of options after agreeing to a $2 billion takeover by Canada's Endeavour Mining Corp.
The payout is "egregious" given Teranga's relatively small market cap, said portfolio manager Coille van Alphen at precious metals-focused fund manager Equinox Partners, which owns Endeavour shares.
Liquidating stock options shows executives are not invested in the company's long-term future, she added.
"The whole point of a no-premium deal is they create value in the new company," she said. "But if you really believe that, wouldn't you want the upside? Why would you take the cash?"
Teranga said the change of control severance payment - two times annual salary and bonus - aligns with the industry standard.
"Each of the executive officers have been with the company for the better part of the last decade, and the experience of the senior group has played a significant part in our success," Teranga President and CEO Richard Young said in a statement.
Equinox is a member of the Shareholders' Gold Council, launched in 2018 by U.S. hedge fund Paulson & Co. to address high executive pay, cozy board appointments and value-destroying deals.
Endeavour Mining's own change-of-control rules provide for each of its five executives to receive two years' worth of salary and bonus upon termination. Van Eck's Foster said he has previously voted against Endeavour's executive compensation, saying it is "above average".
An Endeavour spokesman said: "The Endeavour Board continually reviews its remuneration policy and takes external advice to ensure that it is appropriate to the size and complexity of the business, while being aligned with shareholder interests. We are in regular dialogue with investors who have consistently approved the policy."
At Kinross Gold Corp, CEO Paul Rollinson and executive vice-president Geoffrey Gold are each entitled to three times their annual salary and bonus, as well as accelerated vesting of equity, if the company is acquired, filings show.
Executives at Canadian miner TMAC Resources Inc will get around C$5.9 million - about 2% of the miner's market capitalisation - if a takeover by Agnico Eagle Mines Ltd goes through.
That is despite a rough ride for long-term shareholders: TMAC listed at C$5.75 per share in July 2015, and will be bought by Agnico for C$2.20 per share.
TMAC CEO Jason Neal declined comment.
(Reporting by Jeff Lewis and Helen Reid; editing by Marguerita Choy)
By Jeff Lewis and Helen Reid