Canadian property giant Brookfield Asset Management Inc. is readying a bid to take a large ownership stake in U.S. mall owner General Growth Properties Inc., according to several people familiar with the matter, aiming to top an unsolicited $10 billion bid made last week by rival mall owner Simon Property Group Inc. Brookfield's planned bid, which could be unveiled as soon as this week, would allow General Growth, to exit Chapter 11 bankruptcy proceedings as a standalone company, with Brookfield as its largest shareholder, these people say.