Shopping center and mini-mall REIT DDR Corp. (NYSE:DDR) is beefing up its property portfolio.

On Wednesday after close of trading, DDR announced that it has agreed to buy out Blackstone's (NYSE:BX) share in multiple shopping centers currently operated by the two firms via a joint venture.

The properties in question include 30 out of 44 shopping centers the companies operate together, and include in particular the "fortress shopping centers" of Shoppers World in Boston, Woodfield Village Green in Chicago, Fairfax Towne Center in Washington, D.C., and Riverdale Village in Minneapolis. Blackstone currently owns a 95% stake in these and the remaining shopping centers DDR is targeting, and DDR intends to pay $1.46 billion -- in cash and potentially also partly in stock -- to buy out its partner. As for the other 14 shopping centers owned by the joint venture, they shall remain 95% owned by Blackstone, 5% by DDR, as previously.

According to DDR, the properties it will be taking exclusive ownership of are very attractive, being located in areas where the average household income is $91,000, and where population density is also high -- an average of 543,000 potential shoppers per market. And because the shopping centers currently charge rental rates slightly "below market," DDR sees the potential to raise prices and boost profits in the acquired target markets.