(Reuters) -The U.S. Justice Department is moving to block UnitedHealth Group's $3.3 billion purchase of Amedisys Inc. over concerns the deal would harm competition in the market for home health services, Bloomberg News reported on Tuesday, citing people familiar with the matter.

The report said antitrust officials have signed off on a lawsuit to be filed in federal court as soon as this week to stop the deal, according to the people, who asked not to be named.

The move follows a meeting last week between company executives and the Justice Department in a last-ditch effort to ease the government's concerns, the report added.

The Justice Department, Amedisys and UnitedHealth did not immediately respond to Reuters requests for comment.