Stakeholders say the organization will help the member agencies coordinate state and federal grant applications for various projects, including housing, transportation and economic development efforts.
Tony Bell, a spokesman for Supervisor Mike Antonovich, said the group would help to "enhance cooperation and collaboration among the agencies."
With the county's membership secured, Glendale City Manager Jim Starbird said the group will likely hold an organizational meeting sometime next month.
"You can be more effective when there are multiple agencies working together," Starbird said. "That's really kind of the bottom line."
The proposed makeup of the body's board includes one representative from each of the seven Los Angeles City Council districts in the San Fernando Valley, one representative from each of the two supervisorial valley districts and one board representative from each of the other member cities.
Each member agency has allocated $10,000 for initial annual dues, which will support administrative costs.
Any board action would require unanimous consent to address initial concerns that one member agency could hold greater power than others — an issue that helped to hold up the group's creation in recent years, Starbird said.
"Most of the time was spent trying to get past those issues of governance and trust," he said.
Supervisors Antonovich and Zev Yaroslavsky will serve as the county's representatives. Glendale Mayor Ara Najarian was appointed last year to serve as the city's representative; in Burbank, City Councilman Jess Talamantes was chosen.
At the time, Talamantes said he was looking forward to being more proactive in working with other agencies across the region.
"It's going to be a good thing," he said. "We've kind of been behind the eight ball in terms of coming together on issues with regional impact."