* RBA interest rate decision due later in the day
* BHP Billiton (LON:BLT) biggest boost to Australia's benchmark index
* Gains largely broad-based in NZ
By Christina Martin
March 6 (Reuters) - Australian shares bounced off fourstraight sessions of declines on Tuesday, with the materials andfinancial sectors outperforming, taking their cue from a jump inoil prices and an upbeat U.S. market.
The S&P/ASX 200 index .AXJO rose 1.3 percent, or 74.5points, to 5,969.5 by 1252 GMT, gaining most in nearly fourweeks. The benchmark closed down 0.6 percent on Monday.
Crude prices thrived on forecasts for robust oil demandgrowth and concerns that output from OPEC producers would growat a much slower pace in coming years, lending support to thematerials and energy sectors. O/R
The metals and mining index .AXMM gained as much as 2.4percent to mark its biggest intraday percentage gain in morethan two weeks.
BHP Billiton Ltd BHP.AX rose more than 3 percent, makingit the top advancer on the main index, while fellow heavyweightRio Tinto Ltd RIO.AX scaled up 0.9 percent.
Pemex, Mexico's state-run oil company, plans to reach out toBHP among others to form new joint ventures for two deepwaterblocks it won in a January auction. stocks rose as much as 1.1 percent, with the 'BigFour' banks adding between 0.1 percent and 1.1 percent,following a rally in U.S. stocks.
Investors moved to the view that Trump's tariffs threat was anegotiating tool after he tweeted that Canada and Mexico couldavoid his proposed tariffs if they ceded ground in the NorthAmerican Free Trade Agreement (NAFTA) talks.
"There is a bit of hope given what we have heard from theU.S. President that the tariffs may be linked to NAFTAnegotiations and may not actually proceed. Now that's notclear-cut obviously; if we get more clarity going the other way,the markets might reverse," said Mathan Somasundaram, marketportfolio strategist at Blue Ocean Equities.
"I think there is still substantial risk in the market butin the shorter term, I think the market is assuming a bit morepositive approach to the tariffs so we've seen a bounce in theU.S. markets and that is flowing through to Australia."
Australia's central bank is seen as all but certain to keepits cash rate at a record low of 1.5 percent at its monthlypolicy meeting next week, a Reuters poll of economists found. AU/INT
Among top gainers on the main index was telecom operatorTelstra Corp Ltd TLS.AX , up as much as more than 2 percent,its biggest intraday percentage gain in nearly five weeks.
Telstra confirmed a deal with News Corp NWSA.O to combineFoxtel and Fox Sports Australia, two months after Australia'scompetition watchdog dropped its opposition to the merger. Zealand's benchmark S&P/NZX 50 index .NZ50 also edgedhigher, up 0.4 percent, or 35.83 points, to 8,315.66.
Utility, healthcare and materials stocks led the gains onthe index, with construction materials maker Fletcher BuildingLtd FBU.NZ being the best performer, rising as much as 3.5percent to its highest in almost two weeks.
Reeling from spiralling costs and deep losses in majorprojects, New Zealand's second-largest company by revenue,flagged in February that losses were NZ$660 million, even largerthan anticipated last year, and that it was exiting thecommercial construction business.