The development, and speculation that Wendel might be interested in a full takeover, gave Saint Gobain a big boost on the stock market. Its shares were trading up 3.18 euros ($4.50), or 4.5%, to 72.61 euros ($102.91), at midday in Paris. Lafarge, another French maker of building supplies was trading up 1.85 euros ($2.55), or 1.9%, to 108.42 euros ($153.80). In London, Wolseley was trading up 16.50 pence (33 cents), or 2.2%, to £8.22 ($16.66).
Wendel fell 2.3%, or 2.77 euros ($3.92), to 118.02 euros ($166.94). The company, which began life as a French steelmaker in 1704, now functions as a kind of closed-end fund specializing in European industrial businesses. It said its 1.6 billion euro ($2.3 billion) Saint gobain stake was a "long-term investment."