March 22 (Reuters) - UnitedHealth Group said on Friday it expects several services related to handling medical claims by its unit Change Healthcare to be online over the next few weeks following a hack last month.

The health insurer said its software for preparing medical claims Assurance went online on Monday, while its largest clearinghouse Relay Exchange will resume on the weekend of March 23.

The insurer expects more than $14 billion in claims referenced to start flowing soon after.

(Reporting by Mariam Sunny and Leroy Leo in Bengaluru; Editing by Krishna Chandra Eluri)