Quick-service sandwich specialist Subway is exploring a sale that could value the company at more than $10B, The Wall Street Journal reports, citing unnamed sources familiar with the situation.

Subway is a sprawling operation, with about 21,100 locations in the United States that did $9.4B in sales in 2021, up 13% from 2020, when the pandemic cut into business. Worldwide, the brand has about 37,000 locations.

In recent years, Subway has been responding to declining sales — a trend for it even before the pandemic — by refashioning its menu items and remodeling stores according to plans it calls “Fresh Forward” design, which includes LED lighting and new floor coverings and colors, QSR reports.

The chain has also been closing low-performing locations under the leadership of CEO John Chidsey, the first person outside the company's founding families to hold that position, which he took in 2019.

A net of 3,650 U.S. locations have been shuttered since 2019 as the company focuses on revamping existing stores and expanding its location count outside the country. Subway's model is 100% franchised, with no company-owned stores.

“Subway [is] a chain with good prospects — even in a slowing economy,” GlobalData Managing Director Neil Saunders wrote in a note Wednesday. “The optimistic outlook is one of the reasons Subway sees this as a reasonable time to explore a sale and why it is likely to attract a significant amount of interest.”

Since its inception in 1965, the Subway franchise of restaurants has been privately held. Its co-founders, Fred DeLuca and Peter Buck, died in recent years.