BRUSSELS, March 5 (Reuters) - Cisco Systems is set to secure unconditional EU antitrust approval for its $28 billion bid for cybersecurity firm Splunk, two people with direct knowledge of the matter said on Tuesday.

The deal announced last year and Cisco's biggest ever will boost its software business amid a boom in artificial intelligence and also help offset a post-pandemic slowdown in demand.

The European Commission is set to clear the deal after its preliminary review ends on March 13 after finding no anti-competitive issues, the people said.

The EU competition enforcer declined to comment. Cisco and Splunk did not immediately respond to requests for comment.

Last month, San Francisco, California-based Splunk said it expects the deal to close towards the end of the current quarter or early in the second quarter of 2024. (Reporting by Foo Yun Chee; editing by Jason Neely)