SINGAPORE, March 14 (Reuters) - Singapore Telecommunications (Singtel) shares fell more than 1% on Thursday in early trade after reports it was in advanced negotiations to sell a significant stake in Australian telco Optus to Brookfield.

The telco had dismissed a separate report by the Australian Financial Review (AFR) on Wednesday that it would sell all of Australia's second-largest telecommunications group for up to A$18 billion ($11.93 billion).

Shares of Singtel were last down 0.8%, after sliding as much as 1.6% earlier in the session. The shares rose more than 4% on Wednesday.

($1 = 1.5092 Australian dollars) (Reporting by Rae Wee; Editing by Jacqueline Wong)