About 50 Citizens branches in the area - most of them inside grocery stores, such as Acmes - already are open seven days a week, and about 120 branches have Saturday hours, Steinour said.
The 161 that will now be open seven days a week include four in South Jersey.
About 250 more employees - from tellers to managers - are being hired, bringing total area jobs to about 2,400, bank officials said.
Evolving customer needs prompted the expansion, Steinour said. "We study these things. We know the number of transactions by every half-hour," he said.
Sunday banking is a convenience for people with very busy midweek lives, he said.
Branches will be open three hours or longer on Sundays, depending on local demand. The bank periodically also adjusts branch hours on other days in response to demand, a spokeswoman said.
Citizens, which is based in Providence, R.I., bought the local branch network of Mellon Bank two years ago, and is the third-largest bank in the Philadelphia region, based on assets.
Neither Wachovia nor PNC, the area's largest banks, offers Sunday banking. Both said yesterday that they offered customers extensive networks of automated teller machines and 24-hour phone and online banking.
"Our customers . . . have told us that banking in a traditional bank on a Sunday is not currently of real significant value to them," PNC spokesman Matt Cabrey said.
The bank, however, continues "to explore this option," he added. In the meantime, PNC customers can take advantage of ATMs that are sophisticated enough to cash checks "to the penny," he said.
Wachovia offers banking by appointment outside normal hours to customers who have complex transactions, bank spokeswoman Barbara Nate said.
Fleet Bank, which also has a substantial local presence, provides Sunday banking here through 23 branches in grocery stores.
Commerce spokesman David Flaherty said its branches tried to provide the kind of customer conveniences that Wal-Mart shoppers expect. Competitors may duplicate the seven-day branch banking concept Commerce has helped to popularize, but "they are unlikely to duplicate the retail mentality," he said.
The local race to provide branch banking on Sundays may be an anomaly nationally, according to the American Bankers Association.
Between 1999 and 2001, there was a slight decline in the number of banks that operated branches on Sundays, according to the association, although its survey did not include banking in nontraditional locations such as supermarkets.
Only 9 percent of banks the size of Citizens were open Sundays, the survey found.
Contact staff writer Porus P. Cooper at 215-854-4761 or firstname.lastname@example.org.