Gulf leaders have ended their summit in Qatar reiterating their desire for a peaceful solution to the conflict over Iran's nuclear ambitions.
Ahmadinejad is the first Iranian leader to attend the GCC summit
The Gulf Co-operation Council's final communique said the body would examine the Iranian president's offer of closer security and economic ties.
It did not mention the US intelligence assessment that said Iran had halted its nuclear arms programme.
Mahmoud Ahmadinejad is the first Iran president to attend a GCC summit.
The final GCC communique also said members would form a common market in 2008 and remained committed to a target date of 2010 for the achievement of monetary union.
"The Gulf common market aims to create one market... raising production efficiency and optimum usage of available resources and improving the six countries' negotiating position among international economic forums," said the final declaration.
Citizens of the six Gulf states will have equal rights to carry out business in any GCC country and equal residency rights.
But BBC economics correspondent Andrew Walker says the most interesting issue for international financial markets was not mentioned - the question of whether Gulf states would stop linking their currencies to the US dollar.
After the meeting, Qatar's prime minister said the policy was for now to stick with the dollar link.
Such policies can help maintain financial stability, our correspondent says, but the recent decline of the dollar in the currency markets has created problems for the Gulf states.
Summit host Qatar welcomed Mr Ahmadinejad's proposals on security and forming an organisation to improve economic co-operation.
"They will be examined by the GCC in a way to reinforce the relations of good neighbourhood and mutual respect... and to contribute to strengthening security and stability in the region," a statement said.
Correspondents say, however, that Mr Ahmadinejad's speech was received coolly by some national delegations and one official was quoted complaining that he had referred to the stretch of water separating Iran and the Arab Gulf states as the "Persian Gulf".
The council, made up of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates was founded in 1980 to strengthen Arab Gulf States after the outbreak of the Iran-Iraq war.