A company owned by the family of Jared Kushner, President Donald Trump's son-in-law and senior adviser, stands to receive more than $400 million from a prominent Chinese company that is investing in the Kushners' marquee Manhattan office tower at 666 Fifth Ave.

The planned $4 billion transaction includes terms that some real estate experts consider unusually favorable for the Kushners. It provides them with both a sizable cash payout from Anbang Insurance Group for a property that has struggled financially and an equity stake in a new partnership.

The details of the agreement, which is being circulated to attract additional investors, were shared with Bloomberg. It would make business partners of Kushner Cos. and Anbang, whose murky links to the Chinese power structure have raised national security concerns over its U.S. investments. In the process, an existing mortgage owed by the Kushners will be slashed to about a fifth of its current amount.