Aug 18 (Reuters) - Malaysia-based International Islamic Liquidity Management Corp (IILM) has lengthened maturities in its Islamic bond programme by auctioning $500 million of four-month sukuk, its first sale of that tenor.

Previously, the IILM has issued three-month and six-month paper, which were introduced to meet a shortage of liquid, investment-grade instruments Islamic banks could trade to manage short-term funding needs.

The IILM sold the four-month sukuk at a profit rate of 1.37389 percent, attracting 17 bids worth a combined $1.3 billion, the Malaysian central bank's website showed.

It also sold $840 million of three-month sukuk at a profit rate of 1.24411 percent, attracting orders of $1.6 billion via 14 bids. The issues were bought by 11 primary dealer banks.

The IILM, a consortium of central banks from Asia, the Middle East and Africa, began issuing sukuk in 2013 under an issuance programme which permits maturities of up to one year.

(Reporting by Bernardo Vizcaino; Editing by Eric Meijer) ((Bernardo.Vizcaino@thomsonreuters.com; Telf: +61293218168; Reuters Messaging: bernardo.vizcaino.thomsonreuters.com@reuters.net))