Ignis Asset Management, which has supported the Glasgow Women's 10k for 16 years, has announced it is to withdraw.
Less than three weeks after this year's event, and a year before the race celebrates its 20th, anniversary the hunt is on for a new sponsor.
Keith Russell, head of sport at race organisers Glasgow Life said: "We have had a great relationship with Ignis – the company has been an incredible supporter of the 10k but the sponsorship agreement has now run its course."
Neither Glasgow Life nor Ignis would comment on the amount of financial support provided as part of the agreement, but Mr Russell added: "We are confident we can financially deliver the event without a title sponsor."
He continued: "The hunt for a new sponsor does not necessarily mean changes to the event – the women's 10k is in a good place at the moment, with 10,000 people taking part."
Next year's run will mark the 20th anniversary of the event, which started with around 800 runners in 1993.
It is now the biggest all-female road race in the UK. The Evening Times has been media partner for more than 15 years and the race raises more than £1 million each year for charity.
Glasgow Life hopes to be able to attract a title sponsor before the end of the year.
A spokeswoman for Ignis said the decision to end the sponsorship deal came, "as part of a wider review of its sponsorship activities".
She added: "Over the last 16 years it has been rewarding and enjoyable for the business and our employees to be integral to the race's growth and success.
"With runner numbers in excess of 12,000, we have decided to hand on the baton to a new partner."