Supermarket chain Morrisons ushered in a new era today as its £3 billion acquisition Safeway finally became part of the group.

Sir Ken Morrison, executive chairman of the enlarged group, hailed the completion of the deal as ''an exciting beginning for our new company''.

Integration of the 479-strong chain of Safeway stores to create a fourth major force in UK food retailing would begin ''quickly and effectively'', he pledged.

Morrisons traded slightly below its opening price at 247.5p today as investors weighed up prospects for the enlarged group.

It brings to an end one of the most hotly-contested takeover battles in recent UK corporate history, involving private investors and all the major supermarket groups.

Bradford-based Morrisons, which sparked the bidding war with a £2.9 billion offer for Safeway in January last year, claimed victory after overcoming competition concerns that ruled out many of its rivals.

The takeover gives Morrisons a greater presence in southern England and increases the pressure on Sainsbury's in the battle to be the UK's third largest supermarket chain.

The enlarged group will operate more than 550 stores, with plans to convert many of the larger Safeway outlets into the Morrisons brand by changing the store design and introducing its own product range.

It is also considering the transformation of 178 medium-size Safeway stores into a ''Morrisons Compact'' brand to compete with rivals such as Tesco, which has a string of ''Metro'' branded stores in town centres.

The takeover brings the curtain down on four decades of history at Safeway, which opened its first supermarket in Bedford in 1962.

Speciality grocer Argyll, which had built up a retail estate since 1977, bought the UK assets of US firm Safeway in 1987 for £681 million to create the chain in its current form.

South American mining group Antofagasta took Safeway's place in the FTSE 100 Index.