War on Want has criticised the Church Commissioners for deciding to continue investing in American firm Caterpillar.
The commissioners, who manage the Church of England's £900m share portfolio, rejected the General Synod's February vote to "disinvest from companies profiting from the illegal occupation of Palestine".
Caterpillar has been criticised for supplying Israel with bulldozers used to destroy Palestinian homes. The American peace activist Rachel Corrie was killed by one of Caterpillar's machines in 2003.
In March, the Church of England's Ethical Investment Advisory Group decided to ignore the Synod vote and reaffirmed its decision not to recommend disinvestment in Caterpillar. The asset committee of the Church Commissioners, which has final responsibility for Church investments, followed its advice.
"This is hugely disappointing," said Nick Dearden, senior campaigns officer at War on Want. "Caterpillar has not apologised for its role in the Israeli occupation, and the Church of England has no evidence that the company is no longer engaged in contracts with the Israeli Army.
"Its products are still used to destroy Palestinian lives and violate international law on a daily basis. It is surely wrong for the Church, or indeed any organisation with an ethical investment policy, to profit from such enormous levels of human suffering."
But the Synod vote has been criticised by Chief Rabbi Jonathan Sacks.
And former Archbishop of Canterbury George Carey has said it made him ashamed to be an Anglican.