The organisation charged with promoting Birmingham is to have the council-funded portion of its budget doubled to £4 million a year.

The increase for Marketing Birmingham is aimed at boosting the city's image by attracting a wider range of high-profile functions to the NEC, the NIA and the ICC.

The funding decision was taken by the city council cabinet yesterday but described by the local authority's chief executive as a gamble.

It means Marketing Birmingham will have enjoyed an increase of more than 200 per cent in grants from the council since 2004.

The new arrangement, to come into force in 2008/09, will bring Marketing Birmingham's total budget, including commercial income, to about £8.5 million a year.

Council chief executive Stephen Hughes said high-profile events would boost Birmingham's media profile and bring millions of pounds of spending money into the economy. However, Mr Hughes admitted the additional funding might be something of a gamble.

He told the cabinet: "The main risk is in developing the framework but there is a lack of interest in bringing major events to Birmingham. However, this is quite a low risk.

"There is also the risk that the anticipated economic benefits do not materialise."

Mr Hughes added: "The event market is increasingly competitive, both nationally and internationally and an increasing number of cities are beginning to recognise that events are not simply good for the visitor economy, but that they can be used to drive wider economic development across a range of sectors."

He pointed out that China, a country Birmingham wishes to do business with, has 20 convention centres under development, while India is building four centres.

"Birmingham needs to develop a framework that will identify and attract events that will not only bring economic impact but will also bring media profile and marketing opportunities," he said.

"In short, we need to attract events that generate economic benefit but also enhance the image of Birmingham." He said the extra money would be subject to an annual review of Marketing Birmingham's performance against agreed targets.

The new money will enable Marketing Birmingham to establish a sales development fund, with the intention of offering financial incentives to organisations willing to bring conferences and other events to the city.

The council has already agreed a subsidy in an attempt to attract the Rotary International Convention to the NEC in 2013, an event that would generate £25 million in visitor spend for the local economy.

It was confirmed earlier this month that the BBC TV Sports Personality of the Year programme will be staged at the NEC this year, thanks partly to a £50,000 subsidy from Advantage West Midlands.

However, Marketing Birmingham came in for criticism after the Labour Party said it had failed to respond to a request to stage its annual conference at the ICC, a claim officially denied by the council yesterday. A cautionary note was sounded by Ken Hardeman, cabinet member for regeneration. Coun Hardeman (Con Brandwood) said: "If we are bringing major events to Birmingham we have to be absolutely sure we are getting an economic outturn."