Wellington's Round the Bays run is struggling to find a headlining sponsor.
The race, which is the country's third largest "fun run" usually has between 12,000 and 14,500 runners take part, with a total 22,000 involved including volunteers, and family members waiting at the finish line at Kilbirnie Park.
Sport Wellington has run the event for more than 40 years, though this is the longest it's gone without a top-tier sponsor in years.
Chief executive Phil Gibbons said they had been looking for a naming rights sponsor for a while. "We've been out in the market for a while now, looking for a naming rights sponsor. That's proving to be a little bit more difficult than we had first imagined."
The search for sponsorship was taking "core resources" away from the charitable trust's day-to-day operations, he said.
"Having a naming right sponsor of the capability or capacity of AMI or Cigna would relieve a lot of internal pressure and enable us to deliver a more complete event."
Last year it was sponsored by Wellington car dealership company Brendan Foot which stepped in after life insurance company Cigna discontinued its sponsorship deal after four years.
Sport Wellington spokeswoman Kirsten Kilmister said Cigna had chosen instead to use its sponsorship funds to sponsor 10 kilometre runs in Hawke's Bay and Queenstown International Marathons.
"We have to pay for all the road closures, for the big trucks that go around and put all the cones out and the signs to go up. It's a lot of cost."
She would not say how much money naming rights sponsors committed to the event.
Gibbons said Cigna's move from sponsoring the event was "quite reflective of the market for sponsorship".
"This is a large community event, it's not an event that draws international participants or participants from all corners of NZ. We are competing with those big nationwide events."
A number of businesses had done "due diligence" to see what it would mean to become Round the Bay's biggest sponsor.
"A lot want to be involved but not at that top-level."
With four months left before registrations open, Sports Wellington is hoping to secure a big name sponsor by August.
Gibbons said a meeting with Wellington City Council to see if it might want to become a partner was cancelled at the last minute.
Council spokeswoman Victoria Barton-Chapple said there had been no discussion with Mayor Justin Lester about funding for Round the Bays.
"While we support the event, Wellington City Council won't be funding it."
Councillor Simon Woolf, who oversees the council's sport portfolio, said Sport Wellington would "absolutely be able to [find a naming sponsor] because it's one of those events that's absolutely iconic in Wellington".
"Any business that puts its name to the event is going to get a great return on brand association and in doing so they're assisting the community."