Wim Kok, a trade unionist-turned-politician who became prime minister of the Netherlands as one of a new breed of pragmatic Social Democratic leaders who swept to power in Europe in the 1990s, died on Saturday in Amsterdam. He was 80.

Prime Minister Mark Rutte announced the death without providing other details. Some European news organizations reported that the cause was heart failure and that he had died in a hospital.

Mr. Kok hitched his Dutch Labor Party to the right-wing Liberal Party and to the centrist Democrats 66 to form two ruling coalitions that steered the Netherlands to economic recovery and then strong growth from 1994 to 2002.

He was an exponent of the moderate center-left brand of politics that Prime Minister Tony Blair of Britain and President Bill Clinton personified at the time. Mr. Kok developed a rapport with both men. Mr. Blair once praised him as “one of the greatest people in politics today.”