June 25 (Reuters) - European shares closed at a record high on Thursday, boosted by a surge in healthcare stocks, while a rebound in artificial intelligence-related shares, driven by strong forecasts from Micron and Qualcomm, provided additional support at the start of the session.

The pan-European STOXX 600 index closed 0.8 percent higher at a record high of 640.21 points, after hitting a session high of 642.09 points. This was its biggest daily gain in nearly two weeks.

Healthcare stocks were among the biggest supporters of the index, rising 1.5 percent.

Bayer's stock jumped about 18.7 percent, topping the gains of the Stoxx 600 index, after it achieved a legal victory in which the US Supreme Court blocked thousands of lawsuits accusing the company of failing to warn users that the active ingredient in its Roundup herbicide causes cancer.

Meanwhile, a surge in technology stocks helped push the Stoxx 600 index to its highest level of the session, before it later lost momentum.

The sector ended trading up 0.8 percent, after rising as much as 2.5 percent during the session. Strong forecasts from Micron and Qualcomm helped to ease investor concerns that the global AI stock rally had peaked.

Shares of Infineon and STMicroelectronics rose 3.1 percent and 5.1 percent respectively, while shares of ASML, a supplier of semiconductor equipment, climbed 2.6 percent.

Shares of Siemens Energy, a company specializing in artificial intelligence equipment, rose 2.3 percent.

Martin Fransden, portfolio manager at Principal Asset Management, said, "Although Europe is somewhat lacking in technology leaders, some companies are still in a position to reap tangible benefits from this trend."

Shares in EasyJet jumped 6.4 percent after the British low-cost airline rejected a fourth takeover bid from US investment firm Castle Lake.

Shares in German automaker Volkswagen rose 1.3 percent after it agreed to sell its Everlens diesel engine unit to Bain Capital in a deal worth around 7.4 billion euros ($8.4 billion).