China has accelerated purchases of Saudi crude oil for January to the highest volumes in five months, after the world’s top crude exporter slashed its official selling prices for Asia to the lowest premium over benchmarks in five years. Chinese refiners have nominated almost 50 million barrels in total of Saudi crude volumes for January loading, anonymous traders with knowledge of the purchases told Bloomberg on Tuesday. The nominations for January are about 10 million barrels higher compared to the December volumes and the highest level…