Aug 28 (Reuters) - U.S. Senators Ron Wyden and Elizabeth

Warren wrote a letter to UnitedHealth ( UNH ) executives asking

for information about the loans the healthcare conglomerate

provided after the cyberattack at its tech unit last year.

In a letter to UnitedHealth ( UNH ) CEO Stephen Hemsley and the

group's industrial bank Optum Financial's chief executive,

Dhivya Suryadevara, senators expressed concern over reports that

the company used aggressive tactics to demand immediate loan

repayments from healthcare providers, including threats to

withhold payment for doctors' health insurance claims, if they

do not pay in full immediately.

The cyberattack at Change Healthcare - the largest

healthcare data breach in the United States to date - caused

widespread disruptions in claims processing and impacted

patients and providers across the country.

UnitedHealth ( UNH ) loaned out more than $9 billion to providers

who had been struggling after the massive ransomware attack in

February last year.

"Now, more than 15 months after systems restoration and 14

months after the federal government ended its own assistance

program, we have worked collaboratively with thousands of

providers across the country to help them satisfy the repayment

responsibilities they agreed to when accepting funds," Change

Healthcare said in an emailed statement on Thursday, adding that

it remains open to "reasonable repayment arrangements."

In the letter, dated Wednesday, the Democratic senators

asked for data indicating the total number of loans provided,

the criteria used to issue loans, copies of repayment plans,

among others.

The company is expected to respond to the queries no later

than September 12.