FRANKFURT, Sept 15 (Reuters) - Siemens is readying its logistics unit for sale in a potential roughly 500 million euro ($591 million) deal, as the German industrial conglomerate sheds non-core businesses to focus on its industrial operations, people close to the matter said.

The company is working with an advisor on the divestiture of Siemens Logistics, which makes gear to unload, convey, sort and code parcels and prepare letters for delivery, they said, adding that an auction could launch as early as late-2021.

The airport logistics business - machines to handle baggage and cargo - is not part of the operations up for sale, but will be offloaded at a later stage when air traffic has rebounded from the hit it took in the pandemic, they added.

Siemens declined to comment.

The Siemens logistics operations put up for sale have annual core earnings of about 50 million euros and could be valued at more than 10 times that, the sources said.

Siemens already tried to offload the unit in 2014, but at the time failed to strike a deal with buyout group Triton and later with U.S. investor Wilbur Ross.

The business competes with the likes of Toyota-owned Vanderlande, Honeywell, Kion, Daifuku and Interroll and MHS Houten, which are expected to be targeted as possible buyers in the auction as are private equity groups, the sources said.

Siemens Logistics, which counts DHL, UPS and Amazon among its customers, saw strong growth in the April-June quarter, mainly in package handling operations, Siemens said in its third-quarter earnings release last month.

Siemens has been reshaping itself over the last few years, listing its Healthineers and Siemens Energy divisions and selling smaller operations like mechanical drives unit Flender.

A number of non-core activities dubbed portfolio companies remain, but one other one is also currently on the market: Yunex Traffic unit, formerly known as Intelligent Traffic Systems.

Siemens is expected to send out information memorandums on the traffic light technology and equipment maker later this month.

Yunex, which is witnessing growth in the higher single-digits, has annual core earnings of about 60 million euros and could be valued at 12-14 times that, people close to the matter said.

Siemens is working with Morgan Stanley on the Yunex divestiture, they added.

Morgan Stanley declined to comment. ($1 = 0.8463 euros) (Reporting by Arno Schuetze; Editing by Emelia Sithole-Matarise)