LONDON, June 15 (Reuters) - U.S. Treasury yields fell to a one-month low on Monday as oil prices slid after the U.S. and Iran announced a preliminary agreement to end their conflict and reopen the Strait of Hormuz.

The yield on 10-year Treasury notes US10YT=RR fell to 4.4197%, the lowest since May 12, and was last down 4 basis points (bps) at 4.441%. Yields move inversely to prices.

U.S. President Donald Trump said the Strait of Hormuz, through which a fifth of global oil and gas typically flows, would reopen on Friday and that he had ordered the end of the U.S. blockade on Iranian ports.

WTI oil CLc1, the U.S. benchmark, was last down more than 5% to just above $80 a barrel, its lowest since early March.

Yet the deal leaves many issues unresolved. Iran's deputy foreign minister, Kazem Gharibabadi, said a more expansive agreement on the wider conflict would be negotiated during a 60-day ceasefire period.

The key issue for bonds and other markets, however, is the reopening of the Strait of Hormuz. Its closure has pushed oil prices sharply higher and led to traders scrubbing out previous bets on Federal Reserve rate cuts.

Two-year U.S. Treasury yields US2YT=RR, which are sensitive to Fed expectations, fell 5 bps on Monday to 4.033% in a sign that traders were reducing their bets on the chance of a rate hike this year.

"Markets are now revisiting their central bank pricing in what now seems to be a short-lived macro event," said Florian Ielpo, head of macro at Lombard Odier Investment Managers.

Yet analysts cautioned that the disruption to energy markets means oil and gas prices are unlikely to fall straight to pre-war levels and could continue to boost inflation.

U.S. oil was still 20% higher on Monday than when the war began in late February.

"This feels like the end of the oil drama, but not yet the end of the inflation drama," Ielpo said.

The Fed is widely expected to keep interest rates on hold on Thursday when it makes its first decision with Kevin Warsh as chair, but traders will be watching closely for signals about how the central bank will deal with inflation, which hit a three-year high in May.