Brookfield is offering a higher cash component in its ongoing bid to acquire GGP.

The new bid comes three months after GGP rejected a $14.8B offer from Brookfield. Details of Brookfield's latest offer are not public, but it is believed Brookfield is offering GGP shareholders more cash in the deal and a new security which would trade as a REIT, Reuters reports.

GGP stock opened trading Monday at $22.14/share, before falling to $21.48. The equity component of the deal has become a stumbling block in the Brookfield-GGP negotiations. The new federal tax package and its impact on mergers and acquisitions has extended negotiations between the two firms, as well.

If Brookfield's offer is accepted, the combined company would be one of the world's largest retail real estate conglomerates. Experts have said it would have more power to negotiate favorable leases with retailers, and put Brookfield-GGP on a par with Unibail, which acquired Westfield for $16B last December to become the world's largest shopping mall operator. Part of what made that deal happen was Westfield's scaling back of its portfolio to only assets in high-performing markets.