Updates with more detail on results from paragraph 2 onwards

Feb 20 (Reuters) - Australia's Telstra TLS.AX reported a 6.5% rise in its half-year profit on Thursday, as the country's top telecom company benefited from strong performance across its segments.

The company also announced a A$750 million ($475.88 million) buyback, which it said was consistent with its "capital management framework" and demonstrated confidence in its "financial strength and outlook".

Its net profit attributable was A$1.03 billion, in line with the Visible Alpha consensus estimate and ahead of the A$964 million reported a year ago.

Telstra's consumer division, its biggest profit-generating segment, saw total income grow 3.1% to A$5.53 billion on growth in mobile business.

The top telecom firm said it would invest A$800 million over the next four years to upgrade its mobile network and that it remained on track to reduce its core fixed costs by A$350 million by the end of the current fiscal year.

Telstra declared an interim dividend of 9.5 Australian cents per share. Its last year's payout was 9 Australian cents apiece.

($1 = 1.5760 Australian dollars)

(Reporting by Sameer Manekar and Sneha Kumar in Bengaluru; Editing by Shilpi Majumdar)

((Sameer.Manekar@thomsonreuters.com;Sneha.Kumar@thomsonreuters.com;))