The Avenue of the Arts has "primarily focused" on South Broad, with its theater, orchestra and restaurant scene, he said.
Now, he said, institutions on North Broad will not have to compete with South Broad for attention and fundraising efforts.
Clarke, widely considered a 2016 mayoral candidate, was surrounded by representatives of a number of organizations, businesses, labor unions and Temple University personnel at a news conference at Tower Place, an apartment complex at Broad and Spring Garden streets owned by developer Bart Blatstein.
Mark McDonald, Mayor Nutter's spokesman, said he had no record of the mayor having been invited to the news conference.
But McDonald added: "The administration believes that organizations that are set up to help manage public space are always a good thing. We look forward to learning more about this particular announcement."
An hour before Clarke's announcement, Nutter was at a news conference announcing the groundbreaking of a 49-story FMC Tower at Cira Centre South at 30th and Walnut streets.
Meanwhile, at Clarke's announcement, Blatstein said he hopes to win the second casino license for his project at the former Daily News and Inquirer building at Broad at Callowhill streets.
Ken Scott, president of Beech Interplex, said the coalition on North Broad would include nonprofit organizations, religious institutions, labor unions and developers.
"The idea is everyone will have a seat at the table," Scott said.
Clarke said the group may seek to create a business-improvement district similar to the Center City District. Community members rejected a previous attempt by Clarke to create a Neighborhood Improvement District.
In the meantime, Clarke said, the new coalition and Avenue of the Arts would work together. The streetscape project planned for North Broad was started by Avenue of the Arts.
Kenneth Lawrence Jr., Temple University's senior vice president for government, community and public affairs, said: "North Broad is our front door. We plan to be a significant player within the new organization."
On Twitter: @ValerieRussDN