* Duterte orders closure from April 26 over environment woes
* Businesses want time to prepare; tens of thousands affected
* Boracay drew 2 million tourists in 2017
* Airlines offer refunds, cut back flights
By Neil Jerome Morales
MANILA, April 5 (Reuters) - A decision by the Philippines to close the holiday hotspot of Boracay, which President Rodrigo Duterte has called a "cesspool", prompted airlines Thursday to cut back flights to the island, while business groups called for the decision to be reconsidered.
The abrupt presidential order to close Boracay to tourism for six months from April 26, aimed at rescuing the once idyllic island from ruin, was issued Wednesday.
Cebu Pacific, the dominant domestic carrier, said it cancelled 14 daily round-trip flights to Caticlan and Kalibo, Boracay's two main gateways, from April 26 to Oct. 25, while Philippine Airlines said it would scale down services to the airports and add flights to other destinations.
Discovery World Corp, which operates an 88-room resort in Boracay, said Thursday that the closure would have a significant impact on its financial health, citing the resort's large contribution to revenue. The company's shares dropped 7.5 percent on Thursday.
The Philippine tourism minister, Wanda Teo, said Thursday that businesses and visitors to the crowded 10-square-kilometre (4-sq-mile) island would have to make a sacrifice.
"If you close one establishment but open another, tourists will still come. All establishments, whether compliant or not, will be closed," Teo told ANC news channel. "Everyone must sacrifice here."
The tourism industry urged a less drastic approach to rehabilitating the island and to delay the planned closure.
Jose Clemente, president of the Tourism Congress of the Philippines, said businesses were aware of Duterte's planned cleanup, but hoped for a partial or phased closure, and more time to adjust.
"We are a bit depressed right now in the industry," he said. "I really feel for the people in Boracay," he added. "They really need to find ways to be employed, or at least keep their head above water for the next six months."
Located off the northern tip of the central island of Panay, Boracay's white sand, lively night scene and abundant water sports attracted nearly 2 million visitors last year, with the largest contingents coming from China and South Korea.
In closing the island to visitors, Duterte, known for his no-nonsense style, was responding to numerous government inspections following his criticism in February of sanitary conditions on the island.
Duterte was furious about sewage problems stemming from inadequate treatment systems and unrestrained development of businesses, which in many cases were operating without permits.
It is not immediately clear what the government plans to do during the closure and what the rehabilitation of the island might entail. A six-month closure could shave 0.1 percent off the country's gross domestic product, according to a government estimate on Tuesday.
Wastewater management is expected to be the priority, after inspections discovered businesses releasing untreated sewage into the sea.
Boracay is one of 7,300 islands in the archipelago nation and hosts 1,800 businesses, including global hotel chains like Shangri-La and Movenpick, and locally listed companies Megaworld Corp and Manila Water.
Philippine Airlines said it supported the government's decision.
"We fully support the government's intention to make Boracay fully safe and environmentally friendly," said Jaime Bautista, the airline's president.
Both Philippine Airlines and Cebu Pacific offered customers full refunds or flights elsewhere, and said they would still operate a limited number of flights to Caticlan and Kalibo airports to serve residents, which number about 50,000.
Airlines offer around 1.2 million seats from Boracay's Caticlan airport annually, nearly three-quarters from the capital Manila, data from Aviation Consultants show.
"Cebu Pacific with some 323,000 odd seats a year from the Island would be the largest carrier disrupted," said John Grant, director of JG Aviation Consultants.
Discovery World said it has started to refund customer deposits, rebooking them to future dates or to its resort on the island of Palawan.
"Our plan is to downsize to a skeletal team for the upkeep and maintenance of the resort during the period," it said in a statement, referring to the Boracay facility. (Additional reporting by Jamie Freed in SINGAPORE; Writing by Neil Jerome Morales and Martin Petty; Editing by Philip McClellan)