June 23 (Reuters) - Most Gulf stock markets ended lower on Tuesday, as investors grew more cautious amid progress in U.S.-Iranian talks and increasing expectations that the Federal Reserve will take a tougher stance on inflation later this year.

The waiver granted by the United States on Monday allows Iran to sell oil for 60 days as part of a peace agreement to end hostilities in the Middle East, causing oil prices to fall by more than three percent and giving a boost to financial markets in the Gulf.

U.S. Vice President J.D. Vance said that progress had been made in talks with Iran and that the Strait of Hormuz was open.

Brent crude futures fell 26 cents, or about 0.3 percent, to $77.64 a barrel on Tuesday.

The Saudi index fell 0.4 percent, affected by a 1.3 percent drop in shares of Saudi Basic Industries Corp. (SABIC) and a 0.2 percent decline in shares of Saudi Aramco.

In Qatar, the index fell 0.4 percent, due to a one percent drop in shares of Qatar Industries.

George Pavel, general manager at Naga.com, said that investors are watching the diplomatic process closely, and any sign of progress is likely to boost sentiment in GCC markets.

He added that stocks in the region may remain driven by oil market movements, as a decline in crude oil prices is likely to affect stocks, but a recovery in shipping traffic in the Strait of Hormuz and an increase in energy exports may help limit the decline, noting that markets will remain vigilant for further developments in the talks and their impact on the recovery of shipping traffic.

The index in Dubai fell 1.3 percent, affected by a 2.3 percent drop in shares of Emaar Properties.

In Abu Dhabi, the index fell 0.1 percent, while the index in Bahrain declined 0.3 percent, the Omani index lost 1.2 percent, and the index in Kuwait also fell 0.4 percent.

Increased expectations that the US Federal Reserve will accelerate its interest rate hike schedule under new Governor Kevin Warsh have put further pressure on the global market.

Gulf markets tend to track shifts in US monetary policy expectations, as most of the region's currencies are pegged to the dollar.

Outside the Gulf region, Egypt's blue-chip index fell 1.6 percent.