Takeovers among U.S. real estate investment trusts are poised to accelerate as shareholder activism increases and executives become more receptive to deals, according to research firm Green Street Advisors LLC.

The number of transactions involving sizable REITs, through mergers of public companies or privatizations, has plunged almost 80 percent in the past seven years compared with 2000 to mid-2007, when there were 32 deals, Newport Beach, Calif.-based Green Street said in a report. Conditions “now appear ripe” to end the drought, the firm said.