Tesco's £4 billion takeover of Booker has completed, both companies said today, creating a new powerhouse in Britain's £200 billion a year food market.

The cash and shares deal to combine Tesco, Britain's biggest retailer, with Booker, the country's largest wholesaler, received court approval on Friday and is now in effect. 

The deal received regulatory approval in December and both sets of shareholders backed the plan last Wednesday. 

Booker shares have now been de-listed from the London Stock Exchange. For each Booker share Tesco offered 0.861 new Tesco shares and 42.6 pence in cash. 

Tesco shares closed on Friday at 202 pence. 

Analysts noted that with a market capitalisation of just under £20 billion, Tesco is now bigger than the whole of rivals Sainsbury's, Morrisons, Marks & Spencer and Ocado put together. 

Tesco will now start its "Joining Forces" programme to integrate the two businesses. 

Charles Wilson, formerly Booker's chief executive, takes over as CEO of Tesco's retail and wholesale operations in the UK and Ireland reporting to group CEO Dave Lewis. 

Stewart Gilliland, formerly Booker chairman, will become a non-executive director of Tesco.