News: WBC Australia, NZ shares down as markets brace for Fed outcome

(Updates to close)

Dec 13 (Reuters) - Australia shares stepped back on Tuesday as investors were wary before the Federal Reserve meeting, where it is expected to raise interest rates and provide a steer on future monetary policy in the wake of Republican Donald Trump's election win last month.

The S&P/ASX 200 index (xjo) fell 17.8 points or 0.32 percent to 5,545 at the close of trade, snapping five consecutive winning sessions.

Commodity firms and financials made up more than two-thirds of the losses on the index, offsetting gains from real estate and healthcare shares.

Miner Fortescue Metals (FMG) fell 6 percent for its biggest one-day slide in six months, pressured by falls in commodity prices.

Commodities tend to move lower when real interest rates rise as supply increases and capital flows into higher yielding assets.

Global miner Rio Tinto (RIO) slipped 2.5 percent, while BHP Billiton (BHP) spin-off, South32 lost 2 percent.

Financial stocks .AXFJ slipped 0.6 percent, tracking their U.S. peers .SPSY. and ending a five-session streak of gains.

Westpac Banking Corp (WBC) was the biggest drag, while the other three of the 'Big four' fell between 0.6 percent to 0.2 percent.

Among the gainers, Telstra (TLS) added 0.2 percent, while biopharma firm CSL Ltd (CSL) added 3.2 percent, and was the biggest percentage gainer on the index.

New Zealand's benchmark S&P/NZX 50 index (nz50) fell for the third day, down 0.4 percent or 25.8 points to finish at 6850.2.

Losses were led by healthcare stocks. Ryman Healthcare (RYM) lost about 2.23 percent, while Fisher & Paykel Healthcare (FPH) shaved off 1.3 percent.