Diamond, who was given $14.1 million in total compensation in 2010, was awarded $10.3 million in 2011, The New York Times reported.
For 2011, Diamond is to receive $4.2 million in deferred shares and $2.1 million in salary.
In an annual report, the bank's remuneration committee wrote while pay was a reflection of performance, "in making these decisions, we are mindful of current economic conditions."
Big banks in developed countries have had their executive pay intensely scrutinized since the financial crisis hit in 2008. For 2011, the CEOs of the Royal Bank of Scotland and Lloyds Banking Group turned down their bonuses, the Times said.
Both RBS and Lloyds are partly owned by the government.
At Barclays, the bonus pool shrank by 25 percent in 2011 compared with 2010, with the top executives taking on the lion's share of the cutbacks.
For top executives, bonus pay was cut an average of 48 percent, The Times said.