Askhad Orazbae, the group's secretary-general, announced the news to journalists at the conclusion of the summit's main meeting in Dushanbe.
"I think the creation of this fund, of course, cannot resolve all of Afghanistan's problems," Orazbae said. "But from a political point of view, it is very important to demonstrate our solidarity with the Afghan people and to show our readiness to provide concrete support for Afghanistan's reconstruction -- and the recovery of the economy after the devastation of Afghanistan."
So far, Pakistan is the only ECO member that has announced a pledge to the fund.
Pakistan, which seeks to build a pipeline to carry Turkmen natural gas across western Afghanistan to a distribution center in southern Pakistan, has promised to contribute $5 million to the fund.
Tajikistan's President Imomali Rakhmonov confirmed that money from the fund would be used to finance regional energy projects.
He also suggested the fund could be used for infrastructure projects, such as a proposed highway link between Iran and Tajikistan that would pass through northern Afghanistan:
"The leaders of [ECO] states and governments believe that our organization has reached such a level of maturity that it can actively and directly help implement large-scale, economically profitable projects of regional importance -- including hydro-energy projects, infrastructure, industrial and hydro-economic projects that contribute the most to the strengthening of the economic potential and progress in our larger region," Rakhmonov said.
At the conclusion of the formal summit sessions, Rakhmonov held a private meeting with Afghan Transitional Administration Chairman Hamid Karzai and President Hojatoleslam Mohammad Khatami of Iran. Tajik government officials told RFE/RL that the three-way talks focused on the proposed Iran-Tajikistan highway through northern Afghanistan.
Svante Cornell is a research director of the Contemporary Silk Road Studies Program at Uppsala University in Sweden. He told RFE/RL that it is the interest of both Iran and Tajikistan to build the highway through northern Afghanistan.
"Given the present situation where Tajikistan is economically and trade-wise isolated from Uzbekistan, its opportunities to conduct trade are crucial," Cornell said. "And in this sense, opening up to the south -- and potentially to South Asia or the Middle East, including Iran -- is of paramount importance for any kind of economic development in the country."
Cornell noted that by passing through northern Afghanistan and into Tajikistan, the proposed highway would link together several regions where Persian or the closely related Dari language are spoken.
"Tajikistan, for both cultural and political reasons, is the country that has been the most positive toward Iranian involvement in the region," Cornell said. "Other countries in Central Asia have been wary of Iran. Tajikistan is really the main inroad for Iran into Central Asia. And the changes in Afghanistan have, of course, made it possible for the Iranians to figure [create] a type of Persian cultural zone that stretches from Iran to Tajikistan."
But Cornell said that other ECO countries in the region -- such as Kazakhstan, Kyrgyzstan, Uzbekistan, and Turkmenistan -- will not benefit directly from the proposed highway. They are therefore unlikely to contribute significantly to that project. The two other ECO members are Azerbaijan and Turkey.
(Sojida Djakhfarova from RFE/RL's Tajik service contributed to this report.)