Nevada Property 1 said in a report that it posted a loss in 2010 after finishing 2009 with an US$ 28.6 million profit.
The company highlighted the Cosmopolitan's US$ 116.5 million preopening expenses as a "major contributor" to its loss. Those start-up costs included a US$42 million marketing campaign.
The US$ 3.9 billion Cosmopolitan opened December 15 and grossed US$ 4.2 million in room rates through the end of the year. The hotel has 2,995 rooms.
The casino made US$ 4.3 million from gambling in the less than three weeks of 2010 that it was open.