The acquisition, approved by the Department for Business, Energy & Industrial Strategy (BEIS) in October, closed just before midnight on Tuesday despite a legal challenge by rival suppliers E.ON, British Gas and Scottish Power.

The extent of government support to Bulb could be less than 4.5 billion pounds, depending on energy prices this winter, BEIS said in a notice published on Wednesday.

Bulb, which had around 1.5 million domestic customers, was one of the largest energy suppliers to collapse last year due to soaring wholesale gas and electricity prices.

($1 = 0.8265 pounds)

(Reporting by Sachin Ravikumar, editing by Paul Sandle)