GLOBAL MARKETS-Oil surges, stocks ease from record highs on tenuous US-Iran ceasefire 

* Brent, WTI crude futures up about 5%

* Nasdaq set to snap longest winning ​streak since 1992

* European ⁠shares fall

* Concerns over Mideast ceasefire grow (Updates to U.S. market ​open)

NEW YORK, April 20 (Reuters) - Wall Street eased from record highs on Monday and oil prices spiked as increasing tensions over the crucial Strait of Hormuz gave ​rise ‌to concerns that the fragile U.S.-Iran ceasefire might not hold.

All three major U.S. stock indexes were modestly lower in early trading, putting the Nasdaq on course to snap ⁠a 13-day winning streak, its longest since January 1992.

But the losses were shallow, held ⁠in check by optimism over solid first-quarter corporate earnings.

"There's ​nothing going on save for the headlines of the day regarding Iran: the Strait (of Hormuz) is closed andwe took a step backward over the weekend," said Peter Tuz, president of Chase Investment Counsel in Charlottesville, Virginia.

"(Investors) have been surprised by how strong some earnings have been, and absent evidence to the ​contrary, I ‌think that's going to continue this week," Tuz added. "That's mitigating the headlines regarding Iran to a great degree." The ceasefire agreement between the United States and Iran appeared to hang in the balance after the U.S. announced it had seized an Iranian cargo ship, prompting vows of retaliation from Iran, which for now is refusing to engage in a new round of peace talks. With no major economic data and a short roster of first-quarter earnings ​reports on Monday, geopolitical tensions in the Middle East were the primary market catalyst. The Dow Jones Industrial Average fell 111.32 points, or 0.23%, to 49,336.11, ‌the S&P 500 fell 17.88 points, or 0.25%, to 7,108.27 and the Nasdaq Composite fell 99.55 points, or 0.41%, to 24,368.49.

European shares slid on growing concerns that the U.S.-Iran ceasefire agreement could collapse after Iran ‌responded to the U.S. seizure of a cargo ship by refusing to participate in a second round of negotiations. MSCI's gauge of stocks across the globe fell 3.04 points, or 0.28%, to 1,071.72. The pan-European STOXX 600 index fell 0.87%, while Europe's broad FTSEurofirst 300 index fell 21.24 points, or 0.85%. Emerging market ​stocks rose 5.12 points, or 0.32%, to 1,602.25. MSCI's broadest index of Asia-Pacific shares outside Japan closed higher by 0.53%, to 819.24, while Japan's Nikkei rose 348.99 points, or 0.60%, to 58,824.89. Fears ‌of ceasefire collapse also sent crude oil prices higher as traffic through the Strait of Hormuz remained largely halted. U.S. crude rose 5.15% to $88.21 a barrel and Brent rose to $94.86 per barrel, up 4.96% on the day.

U.S. Treasury yields edged higher amid mounting geopolitical uncertainty. The yield on benchmark U.S. 10-year ⁠notes rose ⁠2.2 basis points to 4.266%, from 4.244% late on Friday. The 30-year bond yield rose 1.4 basis ‌points to 4.8989% from 4.885% late on Friday. The 2-year note yield, which typically moves in step with interest rate expectations for the Federal Reserve, rose 3.1 basis points to 3.731%, from ​3.7% late on Friday. The dollar index, ​which measures the greenback against a basket of currencies including the yen and the euro, fell ‌0.3% to 98.16, with the euro up 0.09% at $1.1772. Against the Japanese yen, the dollar strengthened 0.07% to 158.72. In cryptocurrencies, bitcoin gained 1.12% to $75,494.92. Ethereum rose 1.12% to $2,306.92.

Gold softened as Treasury yields inched higher. Spot gold fell 0.31% to $4,813.55 an ounce. U.S. gold futures fell 1.04% to $4,807.00 an ounce.