* Telstra to gain from blocking of Vodafone-TPG deal - analysts
* Qantas has best day in more than one month
* Materials stocks fall on lower copper prices, trade tensions (Updates to close)
By Aditya Soni
May 9 (Reuters) - Australian stocks firmed on Thursday, bucking a trend in Asia, as the antitrust regulator's move to block a merger between the country's third and fourth-largest telcos boosted Telstra, while Qantas Airways rose after forecasting record annual revenue.
The S&P/ASX 200 index .AXJO rose 0.4 percent or 26.2 points 6,295.3 at the close of trade. The benchmark dipped 0.4 percent on Wednesday.
However, broader Asian shares .MIAPJ0000PUS fell to an eight-week low as investors steered clear of riskier assets ahead of fresh Chinese and U.S. trade talks, which start later on Thursday.
Beijing has said it will retaliate if Washington increases tariffs on $200 billion of Chinese imports on Friday, a move that could cut global growth.
Telstra Corp TLS.AX , Australia's largest telecom firm, had its best day in over three months and was among the top boosts to the benchmark.
Analysts said that the Australian Competition and Consumer Commission's rejection of a deal between TPG Telecom TPM.AX and Vodafone 's VOD.L Australian joint venture could benefit the ailing telco.
"TPG seemed to be unwilling and probably not able to build a competing 5G network, so Telstra is very much going to have that to itself with Optus," Henry Jennings, senior investment analyst and portfolio manager at Marcus Today newsletter said.
The combined group of TPG and Vodafone would have been a stronger competitor but the decision takes it "out of the game", he added.
TPG shares ended the day 0.3 percent lower after plunging more than 13 percent on Wednesday.
Gains were also underpinned by Australia's largest airline Qantas Airways QAN.AX , as posted its biggest percentage gain since April 2 after reporting a small rise in third-quarter revenue and forecasting record annual revenue. stocks .AXEJ climbed 1.3 percent on the back of strength in oil prices. Oil prices rose 1 percent overnight before trimming some of the gains in Thursday's session.
Woodside Petroleum WPL.AX firmed to a more than one-week high.
In New Zealand, the benchmark S&P/NZX 50 index .NZ50 rose 0.4 percent or 41.3 points to finish at a record high 10,104.35.
The Reserve Bank of New Zealand (RBNZ) lowered the official cash rate to an all-time trough of 1.50 percent on Wednesday.
Auckland International Airport AIA.NZ climbed to its highest since April 2, and Fisher & Paykel Healthcare Corporation FPH.NZ reached a more than two-week peak.