PRAGUE — Borek Sipek, a Czech architect and designer best known in his country for his work for the late Czech president Vaclav Havel, has died at age 66.

Prague’s Vaclav Havel Library announced Mr. Sipek’s death Saturday. He had recently been battling pancreatic cancer.

Mr. Sipek emigrated from communist Czechoslovakia after the 1968 Soviet-led invasion that crushed the liberal reforms known as the Prague Spring. He studied architecture in Germany before establishing a studio in the Netherlands.

He worked with a number of firms, including Driade, Wittmann, Swarovski, Leitner, Quartet, Vitra, Sevres, Saint-Gobain, and Rosenthal.

After the 1989 anticommunist Velvet Revolution led by Havel, his friend, Mr. Sipek became chief architect at the Prague Castle, the seat of the presidency. There he created chandeliers, furniture, and some new entrances.