Sept 21 (Reuters) - Australian shares slid on Thursday, in line with global markets after the U.S. central bank stiffened its hawkish stance, while New Zealand stocks inched higher as the economy grew more than expected in the second quarter.

The S&P/ASX 200 index fell 0.6%, or 41.9 points, to 7,121.4 by 0049 GMT, hitting its lowest level since Aug. 28 and extending losses for a fourth session.

The U.S. Federal Reserve kept interest rates unchanged on Wednesday as widely expected, but signalled another hike by the year-end and much tighter monetary policy through 2024 than previously expected to fight high inflation.

In Australia, heavyweight mining stocks fell 0.7% and were on track for a fourth consecutive session of losses. Sector majors BHP Group and Fortescue declined 0.7% and 0.2%, respectively.

Interest rate-sensitive financial stocks fell 0.6%, with the so-called "big four" banks down between 0.3% and 0.7%.

Energy stocks fell 0.9% and hit their lowest level since Sept. 1 on weak oil prices.

Among individual stocks, Transurban Group slumped 2.7% after the competition regulator opposed the company's plan to acquire a majority interest in Horizon Roads.

New Zealand's benchmark S&P/NZX 50 index advanced 0.1% to 11,342.02 after a two-day slide, as data showed the economy grew more than expected in the second quarter and dodged a technical recession.

Fonterra Co-Operative Group rose 3.9% after its annual profit more than doubled and the dairy company declared a higher final dividend.

Fonterra Shareholder's Fund rose 4.3% and was the biggest gainer in the S&P/NZX 50 index.

(Reporting by John Biju in Bengaluru; Editing by Subhranshu Sahu)