* Aircraft were to be delivered over next two years
* Garuda has 50 737 MAX aircraft on order
* Budget arm Citilink has ordered 25 A320neos (Adds aircraft orders, Airbus and Boeing comment)
JAKARTA, Sept 22 (Reuters) - Indonesia's national airline PT Garuda Indonesia Tbk is in talks with Airbus SE and Boeing Co to delay the delivery of 20 planes, the flag carrier said, as it seeks to better utilise its current fleet and trim costs.
Garuda and its budget unit Citilink were supposed to have taken delivery of the aircraft during the two years through to 2019, Chief Executive Pahala Mansury told reporters on Friday, without giving a new date for the delivery.
"We want to focus on the optimisation of our existing fleet," Mansury said.
Garuda reported a wider net loss for the first half of 2017, hurt partly by the costs of participating in the government's tax amnesty scheme. Following the loss, the state-controlled carrier also sought consent to amend certain terms on its $500 million global sukuk bonds due 2020.
Mansury did not disclose the model of the delayed planes, but Garuda spokesman Ikhsan Rosan told Reuters they are made by Airbus and Boeing, including A320s ordered by Citilink.
"We don't comment on discussions we may or may not be having with customers," an Airbus spokesman said.
A Boeing spokeswoman said the airline worked with Garuda, as with all of its customers, on how to best optimise the airline's fleet.
Citilink has 25 A320neos on order and Garuda has 50 737 MAX aircraft on order, according to the Airbus and Boeing order books.
Reporting by Cindy Silviana; additional reporting by Jamie Freed in Singapore; Writing by Eveline Danubrata; Editing by Christian Schmollinger and Biju Dwarakanath