THE battle of the megga shopping centres begins next month. Blanchardstown Town Centre, which opens on October 16th, is expected to lead to a major upheaval in the Dublin retail market. Three weeks later, the Jervis Shopping Centre begins trading at Mary Street in the centre of Dublin.

Both centres will provide an extra 760,000 square feet of new shopping space - the biggest volume completed in one year.

Blanchardstown will initially have 431,000 square feet - costing over £60 million - but when the second phase is completed next year, it will be the largest shopping complex in the country with more than 650,000 square feet of lettable space. This will be more than The Square in Tallaght, where 55,000 square feet is being added. Another out-of-town shopping centre is planned for Quarryvale, close to the junction of the M50 and the Galway road; however it is not due to open until Christmas, 1998.

For now, Blanchardstown's stylish new regional centre is set to capture a significant share of the retail market at the expense of other shopping centres and traders in the city centre.

Like other out-of-town centres, it will be aimed primarily at shoppers "within a 30-minute radius" by car. Maurice Green, development director of Green Property Company, which is developing the centre, says 60,000 people - more than the population of Galway - live within five minutes' drive of the new centre. Research has also shown more than 600,000 people live within 20 minutes' drive of Blanchardstown.

Access to the complex will be improved greatly when the Northern Cross motorway opens to link Blanchardstown directly with Finglas and Santry. Green Property is providing up to 3,000 car-parking spaces.

Shoppers will undoubtedly be impressed by the vast scale of the complex. The centrepiece is a stunning mall with a three dimensional glazed roof 66 feet high. A parabolic suspended roof marks the entrance to the mall, which is big enough to house three jumbo jets in a nose to tail configuration.

The first half of the mall will be occupied by restaurants and fast-food outlets. They will be located beside UCI's nine cinemas, which will have seating for 2,500 people when they open before Christmas. The inner section of the main mall will be given over mainly to fashion outlets.

The natural fall across the sit9 has allowed architect Andrzej Wejchert to provide two ground floors of shopping opening directly on to car-parks. The layout makes access to both levels easy.

There are six broad malls in all, all of them finished to an exceptionally high standard. Mr Wejchert has opted for reflective materials such as polished stainless steel, ceramic tiles and pillars clad in Japanese reconstituted white glass to give the public areas architectural distinction. The main west mall has a series of voids on the upper level to allow natural light to penetrate through to the lower mall.

The linear-style layout means that the total shop frontage on to the malls will exceed that of Grafton Street. With fashion stores occupying no less than 20 per cent of the entire space, shoppers will have a wide choice. The Sears group alone has taken about 23,000 square feet for six of its fashion and shoe shops.

The anchor tenants, Dunnes Stores and Roches Stores who are fitting out 190,000 square feet on two levels, will occupy 44 per cent of the entire space.

The success of the letting campaign is underlined by the fact that of the 104 outlets available at this stage, only one unit of 750 square feet is still for letting through agents Palmer McCormack.

The rush by UK multiples to gain a foothold in the Irish market proved a boon for Blanchardstown; it is hardly surprising 23 per cent of the space will be filled by traders from Britain and Northern Ireland. One retailer even paid a premium to ensure it got a store.

One of the last traders to agree terms was Argos, which will occupy 9,850 square feet at the front of the centre at a rent of £15 per square foot. The UK multiple will open next spring along with the giant chemists Boots, which will be paying a rent of about £170,000 for 5.500 square feet.

Average Zone A rents are £63 per square foot - almost £100 less than those in Grafton Street.

Maurice Green is hopeful that between 75 and 80 per cent of the traders will be ready for the October 16th opening. The centre will create about 2,000 permanent jobs, according to Mr Green.