Broadway tuner “The Little Mermaid” will shutter Aug. 30, after a run of less than two years.

Disney Theatrical Prods., the legit arm of Disney that produces “Mermaid,” opted to shutter the show in order to avoid the box office slowdown that occurs on the Rialto every September, and also to concentrate on future life for the musical, which is in the planning stages for a fall 2010 tour.

“Mermaid” is one of three Disney tuners currently on Broadway, including long-running hit “The Lion King” and “Mary Poppins,” which opened in November 2006.

The big-budget Main Stem production, said to have been capitalized at north of $15 million and to carry a high running cost, likely did not recoup its initial investment.

Closing makes “Mermaid” one of the shorter-lived Rialto offerings from the Mouse. Org’s first show, “Beauty and Beast,” played 13 years beginning in 1994, while “The Lion King” is coming up on 12 years. The 2000 production of “Aida” ran 4½ years.

Among Disney offerings, only “Tarzan,” the spring 2006 outing that never picked up momentum at the box office and closed after 15 months, has had a shorter lifespan.

“For us, it feels disappointing,” David Schrader, exec veep of Disney Theatrical, acknowledged.

Based on the 1989 animated pic — one of the most popular properties in the Disney stable — the show posted robust sales during its out-of-town tryout in summer 2007.

After a Broadway preview period disrupted by the stagehands’ strike in November of that year, the tuner opened Jan. 10, 2008, earning mixed Gotham reviews but strong sales. “Mermaid” regularly reported weekly B.O. of more than $1 million during its first several months on the boards, particularly during holiday frames and over the summer months of 2008.

But the Rialto’s usual back-to-school downturn hit “Mermaid” particularly hard. The first week of September 2008 saw sales fall by almost 40% and attendance drop to about 70% of capacity.

“Mermaid” will shutter at the end of August to avoid a repeat of that slowdown. “We know what September looked like last year,” Schrader said.

Since that fall, receipts have fluctuated enough to prompt speculation among legiters about the upcoming availability of the “Mermaid” venue, the Lunt-Fontanne Theater. (Incoming tuner “The Addams Family” is said to be a candidate for the space.)

Unlike “Lion King,” which is consistently one of the Rialto’s top earners, “Poppins” also has seen its tallies waver. But Schrader said that show is on more solid footing, in part because “Poppins” recouped its capitalization costs relatively quickly.

He added that Disney Theatrical, which recently adapted the “High School Musical” telepics into popular stage licenses, is working on between 12 and 15 new legit properties, although none are specifically targeted for a splashy Broadway berth. Versions of “Newsies” and “Peter and the Star-Catchers” are among the shows in various stages of development.

Touring version of “Mermaid” will include a retooling of the show’s elaborate set, in order to make the physical production more easily transportable. (The current U.S. tour of “Poppins” includes a similarly modified set.) “Mermaid” also will likely see a handful of productions abroad.

Adapted from the Hans Christian Anderson tale about a young mermaid who trades her voice for a pair of legs, the musical incorporates the Alan Menken-Howard Ashman tuners from the pic, as well as new songs by composer Menken and lyricist Glenn Slater. Doug Wright (“I Am My Own Wife”) penned the book for the show, helmed by Francesca Zambello.

“Mermaid” has so far grossed around $73 million on Broadway. When it shutters Aug. 30, tuner will have played 685 perfs and 50 previews.