The mall wars are heating up. Simon Property Group announced on Friday, March 20th that it had just made its “best and final offer” for rival mall owner Macerich, and boosted its bid by 4.9% to $95.50 from $91.

Of note, the new cash-and-stock offer values Macerich at around $16.8 billion, not including debt.

Macerich in turn said it was reviewing the revised new bid and suggested shareholders take no action yet. The firm rejected Simon’s previous unsolicited proposal, which valued the company at $16 billion, a few days ago, saying the bid was too low.

Simon Property Sweetens Offer For Mall Owner Macerich

Earlier statements

Speaking earlier this week, Macerich Chairman and CEO Art Coppola said the previous offer “substantially undervalues” Macerich and even questioned the structure and legality of Simon’s deal. The mall owner also undertook governance changes (a poison pill and a staggered its board of directors) to protect against unsolicited buyouts.

Simon CEO David Simon commented on Friday before releasing the sweetened bid, “Macerich’s decision to adopt extreme defensive measures is disappointing.”

More on Simon Property bid for Macerich

In its statement, Simon highlighted that the new offer represents a 37% premium to Macerich’s closing price the day before Simon publicly announced its 3.6% investment in Macerich.

Commercial real estate titan Simon, the biggest mall owner in the U.S., is coming after Macerich in an attempt to scale up given the current oversupply of retail space and the increasing volume of online shopping.

Analysts point out that after many years of expansion, mall construction has almost completely dried up. An article in the Wall Street Journal notes according to real estate data firm CoStar Group, an average 193 malls were built in the U.S. every decade from the 1960s through the first decade of the 2000s. However, since 2010, only nine malls have been completed in the U.S., and just two new malls are being built.

Simon Property would end up with a major boost in Arizona and Southern California, where Macerich has a large concentration of properties, if the deal is finalized.