WASHINGTON, May 9 (Reuters) - The U.S. federal human

resources agency at the heart of billionaire Trump adviser Elon

Musk's efforts to slash the federal workforce on Friday canceled

a contract it had awarded to Workday.

The contract for a new cloud-based HR platform, signed on

May 2, was awarded without seeking bids from rivals and had

raised eyebrows among current and former employees of the Office

of Personnel Management.

They had described the sole-source contract as unusual,

given the competition in an industry that includes ADP and SAP

, and expressed surprise to see OPM's largely

successful in-house HR platform on track to be replaced.

On Friday, a federal contracting website page about the

award was updated to state that the award opportunity was

canceled, without elaborating.

OPM and Workday did not immediately respond to requests for

comment. OPM said earlier this month that the sole-source award

was necessary due to "operational failures" and federal mandates

that required immediate action.