Six of the world's most successful modern architects have been shortlisted to help turn the £600 million redevelopment of New Street Station into a landmark gateway to Birmingham.

In a determined effort to respond to criticism that original drawings for the makeover lacked the "wow factor", partners behind the project have cast their net far and wide.

Martin Chambers, the Network Rail programme director in charge of the New Street revamp, said the aim was to find an architect who would bring "magic and excitement" to the new building.

Firms on the shortlist include US-based Rafael Vinoly, responsible for designing the Walkie Talkie building in the City of London and the Bronx Hall of Justice in New York.

Also in the running is London-based Foreign Office Architects, whose portfolio of successful projects includes the Yokohama Ferry Terminal in Japan and the BBC Music Centre at White City, London. FOA is one of four masterplanners for the 2012 London Olympic Games.

Others on the shortlist include Dutch-based UN Studio, designers of the Mercedes Benz Museum in Stuttgart; Australia's Lab Architecture, the practice behind Melbourne's Federation Square; Idom UK, responsible for the Bermondsey Spa regeneration scheme in south London; and Spanish-based Crab.

The winner of the New Street design competition, which is being organised by the Royal Institution of British Architects, will be announced in April.

The successful practice will act as concept architects, redesigning the station's exterior and creating a new atrium at a cost of about £30 million, while working alongside lead consultant Atkins and architect BDP, the firm behind the design of the new Piccadilly Station in Manchester.

BDP will act as delivery architects, tackling infrastructure design, retail elements and the station concourse as well as making the concept "achievable, buildable and affordable", Mr Chambers told Building Design magazine.

"We intend to retain the concept architect throughout to act as a design guardian.

Mr Chambers said whoever was appointed concept architect would have to demonstrate "real flair" and be able to work alongside Atkins and BDP.

Network Rail's initial drawings depicting the station atrium and exterior were criticised by city council regeneration director Clive Dutton last year. Mr Dutton said the design was unexciting and lacked the "wow factor".

The final piece of the New Street jigsaw was put in place last week when Government funding of £400 million was approved, enabling work to begin on the project in 2009 with a projected completion date of summer 2013.

Talks are continuing between the New Street Gateway Plus partnership and the owners of the Pallasades shopping centre.

A number of shops at the Pallasades will disappear in order to create space for the new station atrium.

Shoppers will be able to peer down into the huge light, airy passenger concourse underneath, which will be three and a half times bigger than it is now, allowing a 150 per cent increase in passenger capacity.

A Network Rail spokesman said it was hope an "amicable" agreement could be reached with the Pallasades. The new concourse will be built over two floors of the current NCP car park and other major changes include:

* Airport-style passenger lounges in the concourse, with 42 escalators and 14 lifts connecting to the platforms

Seven public entrances to the station instead of four at present

* A huge glazed public square opposite the Bullring entrance

Mr Chambers added: "The station is important in its own right, it should be putting its own stamp on the cityscape. The ambition is to make it accessible from every angle. There is a lot of work ahead, but this will hopefully promote other regeneration projects in the area."