STOCKHOLM/DUBAI (Reuters) - THE head of an Al-Qaeda-led group in Iraq has offered US$100,000 (S$151,000) for the killing of a Swedish cartoonist for his drawing of Islam's Prophet Mohammad and threatened to attack big Swedish companies.

Abu Omar al-Baghdadi, leader of the self-styled Islamic State in Iraq, also offered US$50,000 to anyone who killed the editor of the newspaper that published the drawing by Lars Vilks depicting the head of the Prophet on the body of a dog.

Sweden's Nerikes Allehanda daily published the drawing, part of a series which art galleries in Sweden had declined to display, last month in what it called a defence of free speech.

Islam does not allow images of the Prophet Mohammad and Muslims consider dogs to be unclean.

The controversy follows violent protests in the Muslim world last year over the publication by a Danish newspaper of cartoons some Muslims felt insulted the Prophet Mohammad. More than 50 people died across Asia, Africa and the Middle East.

Until now, the Swedish image, published on Aug 27, had drawn only diplomatic ire and a small local demonstration.

Sweden's Prime Minister Fredrik Reinfeldt met ambassadors from 22 Muslim countries to try to defuse the row.

'From now on we announce the call to shed the blood of the Lars who dared to insult our Prophet ... and during this munificent month we announce an award worth US$100,000 to the person who kills this infidel criminal,' Baghdadi said in the 31-minute audiotape posted on an Islamist website on Saturday.

'The award will be increased to US$150,000 if he were to be slaughtered like a lamb.

'We know how to force them to withdraw and apologise, and if they don't, they can wait for our strikes on their economy and giant companies such as Ericsson , Volvo, Ikea ...' He also mentioned Scania and Electrolux.