SingTel requested the trading halt pending an announcement, but did not disclose any further details.

The AFR citing sources reported that SingTel was in advanced discussions with Canadian private equity Brookfield to sell Optus in a deal that could value the business for up to A$18 billion ($11.89 billion).

SingTel, Brookfield, and Optus did not immediately respond to Reuters' email requests for comment.

(Reporting by Tom Westbroo and Sameer Manekar; Editing by Kim Coghill and Savio D'Souza)