BlueScope Steel says retail shareholders took up less than half of the new shares available under a $600 million capital raising share offer.

Institutional shareholders took up more than 830 million of the 1.479 billion shares in the entitlement offer, launched to raise funds to repay debt.

The retail component of the offer closed on Wednesday, and only 310 million of the remaining 649 million new shares were taken, BlueScope said on Thursday.

Credit Suisse is to offer the remaining new shares under a book-build.

BlueScope Steel shares have been placed in a trading halt until Monday while that process takes place.

BlueScope shares last traded at 43.5 cents.