Business tycoon Francois Pinault has been given until the start of February by the French authorities to make a bid for Suez, which could leave the French energy giant and its proposed merger partner GDF sweating for near to a month as their plans hang in the balance.

Since as early as September last year, Suez and GDF had hoped to fast-track their merger to completion before the new year. However, a series of legal challenges put pay to any plans to complete in 2006 and now the deal has been left exposed to the potential consequences of elections in early summer.

However, with the merger plan already on the rocks, Mr Pinault has the power to destroy it long before the summer. The billionaire is believed to be considering a bid to buy Suez, which would end hopes of a merger between the two French energy titans.

Now the French Financial Markets Authority has ruled that Mr Pinault has until February 2, 2007 to submit a bid or he must walk away for six months, BusinessWeek has reported. The decision leaves Suez and GDF with a nervous January of waiting.