WASHINGTON, March 27 (Reuters) - The U.S. State

Department on Wednesday offered up to $10 million for

information on the "Blackcat" ransomware gang who hit the

UnitedHealth Group's ( UNH ) tech unit and snarled insurance payments

across America.

"The ALPHV Blackcat ransomware-as-a-service group

compromised computer networks of critical infrastructure sectors

in the United States and worldwide," the department said in a

statement announcing the reward offer.

UnitedHealth ( UNH ) said last week it was beginning to clear a

medical claims backlog of more than $14 billion as it brought

its services back online following the cyberattack, which caused

wide-ranging disruption starting in late February.

UnitedHealth's ( UNH ) tech unit, Change Healthcare, plays a

critical role in processing payments from insurance companies to

practitioners, and the outage caused by the cyberattack has in

some cases left patients and doctors out of pocket. The toll on

the community health centers that serve more than 30 million

poor and uninsured patients

has been especially harsh

.

Hackers said earlier this month that

UnitedHealth ( UNH ) paid a $22 million ransom

in a bid to recover its systems, but whether Blackcat

honored its end of the bargain has not been made public. Shortly

after the hack, the group put a bogus press release on its

website falsely claiming it had been seized by law enforcement,

giving the impression

that they had shut down operations.