(Adds background, judge quote) SYDNEY, Feb 13 (Reuters) - An...

(Adds background, judge quote)

SYDNEY, Feb 13 (Reuters) - An Australian Federal court judge said on Thursday an agreed A$15 billion ($10.1 billion) merger between a local joint venture of Britain's Vodafone Group PLC VOD.L and internet provider TPG Telecom Ltd (TPM) would not lessen competition.

The ruling appears to overturn a decision by antitrust regulator the Australian Competition and the Consumer Commission (ACCC), which blocked the planned deal last year.

The ACCC had said a tie-up between the companies would discourage Vodafone, Australia's second-largest mobile phone company, from entering the internet market and discourage TPG from building a mobile phone network.

However, a merger between the two "would not substantially lessen competition", Federal Court judge John Middleton said in a televised ruling.

Vodafone's Australian joint venture partner Hutchison Telecommunications (HTA) and TPG Telecom were both in a trading halt on Thursday.

($1 = 1.4852 Australian dollars)