Nov 12 (Reuters) - The Justice Department and three U.S.

states filed a lawsuit on Tuesday to block UnitedHealth Group's ( UNH )

$3.3 billion purchase of Amedisys Inc ( AMED ) over

concern the deal would harm competition in the market for home

health services, the department said.

"Eliminating the competition between UnitedHealth ( UNH ) and

Amedisys ( AMED ) would harm patients who receive home health and hospice

services, insurers who contract for home health services, and

nurses who provide home health and hospice services," the

department said in a statement.