Telstra is to sell a 70% stake in its directories business to a private equity firm in the United States for $A454 million.
Under the sale, Telstra will retain a 30% stake in Sensis, which includes the White and Yellow Pages, and will retain whole ownership of its voice services business.
AAP reports the deal valued Sensis at $A649 million.
Analysts earlier put the value of the business at around $3 billion.
Platinum Equity chief executive Tim Gores said the firm would look for new opportunities to develop the business.