The pending purchase of the Wailea Beach Marriott Resort & Spa in Maui by Sunstone Hotel Investors adds to the blistering pace of year-to-date Hawaii hotel transactions, which will hit an estimated $840 million with the closing of this sale.

Sunstone, an Aliso Viejo, Calif.-based lodging real estate investment trust that is entering the Hawaii market for the first time, said Thursday it has agreed to buy the 544-room Wailea property for a net purchase price of $325.7 million from an affiliate of Blackstone Group LP. The transaction, which is not expected to affect hotel operations, should close in the third quarter, Sunstone said.

"Sunstone has been looking in Hawaii for quite some time. It’s a great market with a lot of different demand generators in leisure and group," said Evan Pohaski, Sunstone’s vice president of corporate transactions. "South Maui, specifically Wailea, has always been a prominent resort address on Maui."

The company said it will invest about $65 million in 2015 and 2016 to upgrade the fee-simple property, which sits on 22 waterfront acres adjacent to the Shops at Wailea. The changes, which will focus primarily on public areas, will allow the company to raise the hotel’s average daily room rates, which it believes are $50 a night lower than its competitive set in Kaanapali and about $200 a night lower than rates at other upper-upscale Wailea resorts.

"Wailea is one of the most attractive and supply-constrained leisure and group destinations in the United States," said Sunstone CEO Ken Cruse, who added that the hotel will benefit from Sunstone’s asset management and its repositioning program.

The company said it sees long-term growth for Wailea, which historically has garnered high hotel room rates and strong performance. The latest hotel statistics from Hospitality Advisors LLC show that Wailea’s average daily room rate rose 8.4 percent to $485 and revenue per available room rose 4 percent to $389. While April occupancy dropped 3.4 percentage points, it was still at a packed 80.1 percent.

"Maui has the highest room rates in the state, and Wailea is certainly at the top of that," said Joe Toy, Hospitality Advisors’ president and chief executive officer.

Given the market, Toy said he’s not surprised by the transaction.

"Blackstone is known to be a trader in hotels. They create value and exit," he said. "And we are at the point in the market where most hotel companies are looking at Hawaii as an acquisition target."

Toy said that limited hotel capacity, supply-side constraints and strong demand for Hawaii likely attracted Sunstone. According to its website, Sunstone owns an interest in 29 hotels with 13,740 rooms in the "upper-upscale segment."