June 18 (Reuters) - Australian shares rose slightly on Thursday after the U.S. and Iran released details of their agreement to end the war, while gold stocks limited gains as bullion dropped on prospects of a rate hike by the U.S. Federal Reserve this year.

The S&P/ASX 200 index .AXJO rose 0.1% to 8,974.50 by 0019 GMT, after briefly hitting its highest level since mid-April. The benchmark added 0.5% on Wednesday.

The U.S. and Iran released the text of an interim agreement to end their war on Wednesday, although U.S. President Donald Trump threatened to resume attacks and kill Iranian officials if they failed to honour their commitments.

Financials .AXFJ rose 0.5%, supported by banking heavyweights. Top lender Commonwealth Bank of Australia CBA.AX and Westpac WBC.AX both gained 0.6%. Investment bank Macquarie Group MQG.AX surged as much as 0.5% to a record high.

Meanwhile, shares of fund manager ChallengerCGF.AX rose 0.8% after its unit Fidante agreed to a merger with Channel Capital to create an entity with A$150 billion ($105.41 billion) in assets under management.

Investment firm Washington H. Soul PattinsonSOL.AX gained as much as 1% after divesting some properties of Brickworks' Industrial Joint Venture Trust to Goodman GroupGMG.AX for A$1.89 billion.

Overall gains were limited by gold miners .AXGD, which dropped as precious metal prices fell overnight while prospects of a rate hike this year from the U.S. Federal Reserve grew after rates were left unchanged. GOL/

Evolution Mining EVN.AX fell as much as 3.4%, dropping most in a week, while rival Northern Star Resources NST.AX dropped 2.5%.

Lower iron ore prices weighed on larger miners, with shares of BHP BHP.AX and Rio Tinto RIO.AX dropping 0.4% and 0.9% respectively. That pulled down the mining sub-index .AXMM, which fell 0.7%.

In New Zealand, the benchmark S&P/NZX 50 index .NZ50 fell 0.2% to 13,363.35. Data showed the economy rose 0.8% in the first quarter from the prior quarter, which was in line with analysts' expectations.

($1 = 1.4231 Australian dollars)