Saint Gobain made an offer of 720p a share for BPB which values it at around £3.6 billion. It is an improvement on 675p a share which Saint-Gobain offered a fortnight ago but BPB said it still undervalued the company and its prospects.
BPB, which is listed in the FTSE 100 Index, said: 'The board strongly believes that this unwelcome proposal continues to substantially undervalue the unique position of BPB, its underlying strategic value and attractive growth prospects.'
BPB also unveiled plans today to win over shareholders by returning just over £350 million, equivalent to 70p a share, as soon as it could after the end of the offer period.
It said that for some time it had been considering ways of returning cash and believed now was an appropriate time to bring forward the announcement.
BPB also planned to recommend a total annual dividend of 23p a share for the year to March 31, 2006, an increase of around 44 per cent on last time.