SYDNEY -- A bidding war over Australian casino operator Crown Resorts heated up further on Monday with U.S. private equity group Blackstone raising its offer while domestic rival Star Entertainment Group jumped into the fray with its own proposal. The interest from Blackstone and Star as well as U.S. private equity group Oaktree Capital comes even as two of Crown's three casinos are shuttered and regulatory probes cloud their future. On Monday, a royal commission in Perth began hearings into whether Crown is fit to retain its state gaming license in Western Australia.