Perhaps less welcome to the company's management were reports that the rise had been triggered by rumours that it was being stalked by Nippon Sheet Glass. It has been suggested that Nippon is willing to offer more than 80p a share – or about £1bn – for the world's second-largest glassmaker. The Japanese firm already holds a 20.4% stake. A Nippon spokesperson denied takeover rumours but refused to rule out "future possibilities".
For their parts, City analysts are concerned that one of the UK's biggest business success stories could be sold. One said: "Selling is the last thing on earth Pilkington would want to do – it would be very sad to see it bought."
Some companies in the construction and building materials sector will probably have poured themselves a glass of champers after their bright starts to the new year. Executives at Balfour Beatty and Amec may even have allowed themselves a second glass – Balfour was up 12.2% to 147p and Amec rose 10.7% to 152p.