LaSalle Hotel Properties has rejected yet another offer from competitor Pebblebrook Hotel Trust and is moving forward with plans to merge with Blackstone.

LaSalle's board of trustees announced Monday its shareholders will convene Sept. 6 at the Sofitel Washington D.C. Lafayette Square Hotel to vote on the Blackstone deal, an all-cash transaction valued at $4.8B.

The Bethesda-based REIT filed a proxy statement with the Securities and Exchange Commission Monday for the Blackstone deal, which LaSalle's board unanimously agreed is better than Pebblebrook's offers.

LaSalle announced May 21 its board decided to go with the Blackstone deal. Pebblebrook followed with two proposals to buy LaSalle June 11 and July 20, increasing its offer from the three previous bids it had made before the Blackstone announcement. The REIT's recent offers came at a higher per-share value than Blackstone's but were composed primarily of Pebblebrook shares. LaSalle has maintained its preference for Blackstone's all-cash deal.

Pebblebrook, which owns 9.8% of LaSalle's common shares, said it will vote against the Blackstone merger and expects other investors to do the same.

"We have spoken with the owners of the vast majority of LaSalle common shares, who have all expressed their support for our offer over the Blackstone proposal, and we see no scenario in which shareholders approve Blackstone's take-under deal," Pebblebrook Chairman Jon Bortz said in a release.

LaSalle's portfolio consists of 41 properties totaling 10,400 rooms in 11 markets, including nine in D.C. The REIT is working with Citigroup Global Markets and Goldman Sachs as financial advisers, plus Goodwin Procter and DLA Piper as legal counsel.