Dec 6 (Reuters) -

Regional lender Comerica Bank faces allegations it

systematically mistreated millions of mostly disabled and elder

customers and could pay penalties under new civil enforcement

action, the U.S. watchdog agency for consumer finance announced

Friday.

The Consumer Financial Protection Bureau said it was

suing Comerica ( CMA ) for failing 3.4 million "Direct Express" card

holders -- who the agency said were primarily unbanked people

receiving federal benefits -- by deliberately disconnecting

their phone calls and charging them illegal fees.

In doing so, "Comerica ( CMA ) boosted its bottom line at the

expense of Americans living on a fixed income," Rohit Chopra,

the agency's director, said in a statement.

The Dallas-based bank did not immediately respond to a

request for comment.

The Direct Express program has operated since 2008 under

a U.S. Treasury contract with Comerica ( CMA ) and provides prepaid

debit cards to recipients of federal benefits, according to the

CFPB.

According to the agency, Comerica ( CMA ) vendors intentionally

dropped more than 24 million calls for customers before they

could be connected with bank representatives.

Comerica ( CMA ) also allegedly imposed illegal terms of service

on consumers seeking to stop payments and illegally failed to

investigate account problems.