Low confidence level, as terminology and meanings can vary between countries.
Based on the definitions, "retiro" in the query context (Peru) appears to refer to the handover of property: "Al respecto, el Reglamento considera retiro de bienes, en consecuencia gravados con el IGV, las operaciones de: (i) transferencia de bienes a título gratuito; (ii) apropiación de los bienes de la empresa realizada por su propietario, socio o titular; ..."

bienes inmuebles = immovable goods or assets/ property (real estate)
retiro = recogimiento (DRAE)

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Note added at 2 hrs (2017-05-22 10:39:30 GMT)
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The usual, basic meaning of "retiro" is "withdrawal"or retirement. From the short text except provided, it isn't clear to me whether they mean hiving off or shedding of assets.
https://www.merriam-webster.com/dictionary/hive off

However, I think the notion of transfer is broad enough to cover what is going on.

Whilst I don't disagree with Neils's answer I think this is about a company disposing of its real estate

retiro noun, masculine (plural: retiros m)
retirement n
Los trabajadores mayores de 60 años anunciaron su retiro. The workers over 60 years old announced their retirement.
withdrawal n (plural: withdrawals)
retreat n (plural: retreats)
Cada año voy a un retiro para meditar. Every year I go on a retreat to meditate.
less common: removal n
·
recall n
·
discontinuation n
.
disposal n
·
revocation n
·
drawdown n
·
seclusion n
·
decommissioning n

español term (edited): retiro de bienes muebles

el retiro en nuestra legislación está pensado para bienes muebles, mas no para bienes inmuebles