DETROIT, Michigan - General Motors is preparing to announce a marketing deal between its Chevrolet brand and British soccer club Manchester United.A deal with United would be significant for Chevrolet. The club claims to be the most popular sports franchise in the world; its fan base has doubled in the past five years to 659-million people - nearly 10% of the world's population, the Detroit News reports.GM would not give details about the announcement but said it has scheduled a news media conference with the club on Thursday in Shanghai, China, the centre of GM's largest sales market. GM's marketing chief is to announce a "global sports marketing initiative" in Detroit on May 31.FACEBOOK FRACASThe announcements could also allay concerns about GM's broader marketing strategy. The company has already said it will not advertise during the February 3 Super Bowl because of a steep price increase demanded by CBS, the TV network broadcasting the game. The announcement came just after GM decided to pull $10-million in ads from Facebook because they "weren't effective".GM will, however, keep its own Facebook pages for its cars and trucks, as well as brands. Facebook pages for businesses or brands - like Facebook pages for people - are free. It's the marketing services - links in people's news feeds or ads to the right of the news feed - that cost money.The changes, which involve two of the largest audiences in the US, brought criticism from the advertising and auto industries. It left many wondering about GM's strategy. The Super Bowl audience would have been a perfect for the company, which will introduce new bakkies in 2013.$45bn ADVERTISINGA deal with Manchester United, the DetNews said, "had potential". Most of the club's fans live in emerging markets, according to a survey taken for the club by research firm Kantar. The club claims to have 325-million fans in Asia and 173-million in Africa and the Middle East. It also has 90-million in Europe and 71-million in the Americas. The US has 34-million fans, the club says.GM plans to spend $4.5-billion globally on advertising through 2012, the same amount as in 2011.Manchester United, owned by the American Glazer family, lost the British 2012 Premier League title to Manchester City but the club has been champion a record 19 times.The Kantar survey came from responses of 54 000 people in 39 countries. A similar survey in 2007 indicated that Manchester United had 333-million fans, based on 27 000 responses.