Dec 23 (Reuters) - Foreigners were net sellers of Japanese shares in the week to Dec. 17 on concerns over Omicron coronavirus variant and rate increases signalled by major central banks. They net sold 310.6 billion yen ($2.72 billion) worth of Japanese stocks last week, after buying 239 billion yen worth of shares in the prior week, data from Japanese exchanges showed. Foreign flows into Japanese equities Foreign flows into Japanese equities Overseas investors bought derivatives worth 155.3 billion yen but sold 466 billion yen in cash equity markets. Meanwhile, Japanese investors purchased a net 274.4 billion yen worth of cross-border equities last week, marking a fourth straight week of net buying. Japanese investments abroad Japanese investments abroad Reporting by Patturaja Murugaboopathy in Bengaluru; Editing by Vinay Dwivedi