June 7 (Reuters) - Australian equities fell on Tuesday to their worst session in almost three weeks, as the central bank raised interest rates by the most in 22 years and flagged more tightening to come.

The S&P/ASX 200 index slid 1.53% to 7,095.7, with financial and tech stocks leading the decline.

The Reserve Bank of Australia (RBA) lifted its cash rate by a bigger-than-expected 50 basis points to 0.85%, in a major surprise to investors who had wagered on a move of either 25 or 40 basis points.

"The RBA restored some credibility today by coming out swinging - they may have taken a leaf from the RBNZ's (Reserve Bank of New Zealand) book, but it needed to be done with inflation running so hot," said Matt Simpson, a senior market analyst at City Index.

Financials slipped 2.3% to hit their lowest since March 14. The so-called "Big Four" banks fell between 1.5% and 3.3%, with National Australia Bank leading the decline.

Tech stocks tumbled nearly 3%, with ASX-listed shares of Block Inc losing 2.9%.

Mining, energy and gold stocks all fell as the spectre of further rate hikes loomed.

"We are not sure we are quite at peak RBA hawkishness yet but likely to be edging closer in the coming months against a similar global central bank backdrop," RBC analysts said in a note.

In other news, ASX-listed shares of Yancoal Australia jumped 4.2% after Yankuang Energy, which owns 62.26% of its shares, said it was open to further talks to buy the rest of company.

New Zealand's benchmark S&P/NZX 50 closed 1.3% lower at 11,2657.7. (Reporting By Navya Mittal in Bengaluru; Editing by Subhranshu Sahu)