The FEED and a value engineering assessment both undertaken in recent months by Lycopodium Minerals showed the US$264 million development would be "readily financeable" and would be easily able to services the debts.
Lycopodium was a key contractor at Perseus's Sissingue operation, also in Cote d'Ivoire, which was commissioned earlier this year.
The scope of the VEA included the evaluation of opportunities to improve plant design and optimise the estimated capital expenditure while the FEED progressed the design of the project and allowed a narrowing of cost estimates.
The difference between DFS and FEED costs was a mere $1.2 million
The October 2017 DFS showed an internal rate of return of 27% with a 32-month payback period at a $1250 /ounce gold price based on a 3.3 million tonne per annum mill producing 215,000ozpa with all-in sustaining costs of $734/oz for the first five years of the current 8.5-year life.
Yaoure has measured and indicated resources of 43.1 million tonnes grading 1.39 grams per tonne for 1.93Moz, with 1.5Moz in reserves.
Perseus expects it can produce first gold at Yaoure in before the end of 2020, with the aim of transforming the company into a 500,000ozpa producer by 2022.
The company says it will now advance its finance plan, which involves the deployment of a debt funding package to complement a combination of existing cash reserves and expected future cash flow from Sissingue, and Edikan in Ghana.
Both mines are performing in line with expectations.
In line with guidance, Perseus produced 255,916oz, an increase of 45%, including 147,908oz for the June half.
It is aiming at 260,000-300,000ozpa for fiscal 2019.
Perseus shares were up almost 9% in morning trade to A37.5c, valuing the company at $388 million. It had cash and bullion of $89.8 million at June 30, and debts of $85 million.