Southeastern regional bank BB&T Corp. (BBT) has reached an agreement with the Federal Deposit Insurance Corp. to purchase deposits and branches of Montgomery, Ala.-based Colonial BancGroup Inc. (CNB), according to a person familiar with the situation.

The deal, approved by the FDIC last night, will take effect after the bank is put into receivership, this person said. BB&T, based in Winston-Salem, N.C., has already dispatched employees to Colonial markets to prepare for the takeover.

Colonial has 355 branches in five states and has about $25 billion in assets. It recently said it might not be able to continue as a going concern.

The FDIC and BB&T are expected to announce the agreement later today.

A BB&T spokeswoman said she could not comment on rumor or speculation. A Colonial spokeswoman could not be reached immediately for comment.

An FDIC spokewoman also declined to comment.