Complex sentence: The land on which the station and the KTM railway tracks stood was originally owned by KTM and over which Malaysia had partial sovereignty, till 30 June 2011, when rail service to Tanjong Pagar was ended and the land reverted to Singapore.
Split into simpler sentences: The land on which the station and the KTM railway tracks stood was originally owned by KTM and over which Malaysia had partial sovereignty. This arrangement lasted until 30 June 2011, when rail service to Tanjong Pagar was ended and the land reverted to Singapore.