Bouyges, the French telecoms, utilities and construction group, has invited six private equity houses to make second-round bids for Saur, its water subsidiary, by November 5.

Rothschild is running an auction process that is expected to value Saur at up to €900m ($1.1bn). Private equity interest for the asset includes a joint bid from Candover and Goldman Sachs' principal investment arm, a joint bid from PAI and BC Partners, and individual bids from Eurazeo and Terra Firma.