The parent company of H.Samuel and Ernest Jones is ring-fencing up to $180m (£142m) for opening new stores and refurbs globally this year.
US-based Signet expects the investment to be offset by cost-saving initiatives leveraging technology such as AI, sourcing efficiencies and spend discipline.
The capital expenditure will be spread across 20 to 30 new stores, while 300 of its 2,700 sites will be renovated.
It is not clear how much of the investment will trickle down into its UK portfolio, with the primary focus set to be on its North American Kay, Jared and Diamonds Direct stores, as well as connected commerce capabilities, and digital and technology advancement.
Signet said it was seeing “continued momentum” in the second quarter after suffering a 9% fall in sales to $1.4 billion (£1.10 billion) for the 13 weeks to 4 May.
Operating income fell from $51.9m (£40.9m) to $49.8m (£39.2m).
Signet CEO Virginia Drosos said: “Our results reflect notable acceleration from a sluggish February to the top half of expectations, with an even stronger May. Compared to the previous quarter, we increased North America engagement unit sales by 400 basis points excluding Digital banners.
“Further, customers continue to respond well to our new product offerings and loyalty program, reflected in a meaningful improvement in comparable sales for Fashion since February.
“We expect continued momentum in the second quarter, leading to a positive same store sales inflection in the second half of Fiscal 25.”
