Metro Holdings

[GFG]

DIVESTMENT IN THE ORDINARY COURSE OF BUSINESS BY METRO
HOLDINGS LTD’S WHOLLY-OWNED SUBSIDIARY, ZENSEI TOKUTEI
MOKUTEKI KAISHA OF FRONTIER KOISHIKAWA BUILDING, TOKYO

Metro Holdings Limited (“Metro” or the “Company”) wishes to announce
that Zensei Tokutei Mokuteki Kaisha (“ZTMK”), its indirect wholly-owned
subsidiary, has entered into a Sale and Purchase Agreement (“SPA”) to
sell its interest in the office building, Frontier Koishikawa building in Tokyo,
Japan (the “Property”) to an independent and unrelated party (the
“Divestment”). ZTMK is wholly-owned by Kowa Property Pte Ltd and
Bunkyo Property Pte Ltd, both wholly-owned subsidiaries of Metro Prop
Japan Pte Ltd (“Metro Prop Japan”). Metro Prop Japan is a wholly-owned
subsidiary of Metro Holdings (Japan) Pte Ltd, who in turn is a whollyowned
subsidiary of the Company.

Got an accounting related question about this if there're any pros here that can answer:

"The SPA provides for the sale of the Property for JPY5.22 billion
(equivalent to approximately S$57.7 million)."
"As at 31 March 2015, the Property was carried in the balance sheet of
ZTMK at its valuation of JPY4.79 billion (equivalent to approximately
S$54.8 million)."

"The Divestment of the Property by ZTMK is expected to result in a gain on disposal of investment property estimated at S$4.0 million (net of charges) which will be recognized on completion of the SPA."

Why is the gain on disposal $4mil?
Shouldn't it be 57.7mil - 54.8mil = $2.9mil?
Is it related to currency conversions etc? But even then, the conversion rate should be constant and current right