(Adds TPG's statement in paragraph 3, background on deal in...

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Sept 6 (Reuters) - Australia's TPG Telecom Ltd (TPG) has extended until Oct. 4 an exclusive due diligence period granted to rival Vocus Group for the A$6.3 billion ($4.02 billion) offer for its non-mobile fibre assets.

Discussions between the parties are ongoing and incomplete and its board has not made any decision to accept any offer, TPG said on Wednesday.

"There is no certainty an agreed transaction will eventuate," TPG added.

Reuters in August reported that TPG, one of the country's top telecom firms, had received a non-binding offer from Vocus to buy some of its non-mobile fibre assets.

Vocus, formed by infrastructure investors Macquarie Infrastructure and Aware Super, specialises in wholesale fibre networks.

It has offered to buy certain Enterprise, Government and Wholesale (EGW) assets and associated fixed infrastructure assets, including the wholesale broadband business, Vision Network.

A successful deal would create a combined entity with A$8 billion to A$9 billion enterprise valuation.

The offer comes amid a steady rise in dealmaking in Australia's telecom sector, with firms also reviewing options for their aging infrastructure and capitalise on growth in 5G.

($1 = 1.5684 Australian dollars)