Aug 20 (Reuters) - Shares of Australia's Afterpay Ltd surged to a record high on Thursday after the buy-now-pay-later firm raised its annual core earnings forecast and said Japan's Mitsubishi UFJ Financial Group had taken a roughly 5% stake in it.

Afterpay shares, which have scaled multiple life highs in recent months as online transactions swelled during the coronavirus pandemic, jumped as much as 9.5% to a record A$82.

The company forecast full-year EBITDA of A$44 million ($31.6 million) after markets closed on Wednesday, up from its prior guidance of A$20 million to A$25 million, as it expects losses on customer transactions to be lower than feared.

($1 = 1.3922 Australian dollars) (Reporting by Shashwat Awasthi in Bengaluru; Editing by Tom Hogue)