The biggest shopping centre in Brighton and Hove could get an extra floor under multi-million pound plans for a new conference centre.

An outline blueprint for the new Brighton Centre includes scope to add another level of shops to the £90 million Churchill Square centre.

The new complex could also include a residential tower block, provided it was of a top design.

This area could also include a hotel and better links between Churchill Square and the seafront.

All these ideas are in a planning and design framework document which councillors in Brighton and Hove yesterday agreed should go out for public consultation.

A new conference centre is needed to replace the Brighton Centre, which opened in 1977 and has now become dated.

But the centre will be kept going at least until the end of 2006 and possibly longer if a decision is made to build the replacement on the neighbouring King's West Centre site.

Talks will have to take place with neighbouring landowners, including Standard Life, which runs Churchill Square.

These are crucial because other development on the site will have to pay for the new conference centre.

The replacement centre will only take 1,500 people compared with 5,000 in the existing building but conferences with 2,500 would be able to convene there because other rooms could be used in a more flexible design. There would also be more exhibition space.

The document says there is scope for increasing the height of development on the centre and King's West site, even if no tower is provided.

Any tall building would have to fit in with both the Grand hotel and St Paul's Church in West Street.

Developers would also have to work out how to integrate a rapid transport scheme along the seafront.

Tory councillor David Smith told the environment committee, which approved public consultation on the brief, that it was a "marvellous" project.

Labour property councillor Simon Burgess said: "There is scope for a lot of imagination here. I hope we will end up with better buildings than we have now."

Tory leader Garry Peltzer Dunn said it was vital this development was considered in conjunction with developments at Black Rock and the King Alfred.

Senior Labour councillor Brian Fitch said consultation was vital.

He added: "This gives the opportunity for a world-class conference centre linked to shopping and the seafront."

Environment councillor Gill Mitchell said she wanted to ensure whatever was built had a high element of public safety.

Green councillor Georgia Wrighton said there should be a public meeting.

Consultation will now take place over the next six weeks at Churchill Square and then Hove Town Hall before developers are invited to show interest.