At the stroke of 5 p.m. on Thursday, December 28, the doors of the Harvard Square branch of USTrust, the popular bank that occupies the triangular corner at One JFK St., will close forever.

A letter mailed to all bank customers by the Massachusetts-based bank dated September 28 states: "As is the case at many other banks, we have found it necessary to consolidate the branch system at USTrust."

The letter advised Harvard Square clients to switch their accounts to either the Central Square branch at 671 Mass Ave. or to the Kendall Square branch at 141 Portland St. Accounts that are not transferred will automatically be moved to the Central Square branch, according to the letter.

Cary Saunders, a USTrust customer who works at Harvard's Graduate School of Education, said she is disappointed by the bank's closing because the Harvard Square branch is convenient for her.

"I would rather use a bank that had a branch office in the Square or within walking distance of where I live," she said.

Saunders said she hopes the bank will keep an automated teller machine (ATM) in Harvard Square in order to keep banking convenient for Square-area residents.

"I would be more likely to stay [a customer] if they kept the ATM here," Saunders said.

Several people using the ATM yesterday afternoon said that the branch closing would not affect them.

They held accounts elsewhere and were just using the machine while passing through the Square.

Saunders said she chose USTrust "for the location and for the kind of account I wanted to have."

USTrust offers free ATM service and free checking with a minimum balance.

In addition, clients who maintain a minimum balance of $350 in their interest-bearing checking accounts face no monthly fees.

The bank is especially popular with students because it offers unlimited access to virtually any bank's ATM machines without a service charge, provided that the minimum balance conditions are met.

But with other banking alternatives available in the Square, students still have a plethora of financial options. Saunders said she expects students will be able to find at least as good a deal as USTrust's at another bank.

"If you're a student, you can get at least as good a deal somewhere else," she said.