The Williams F1 team is seeking a new title sponsor now that US telecoms giant AT&T has pulled its support.AT&T branding has been removed from the team's website and list of partners; a team spokeswoman said: "We've concluded our partnership. It expired on December 31 by mutual agreement."Media reports indicated the AT&T deal had been worth around $7-million a season, a comparatively small sum when compared with title sponsorships for many other teams but still an important contribution to the overall budget.CHIPS GO DOWNThe British-based team had its worst season in F1 in 2011 - only five points from 19 races and ninth on the log.The former World champion team lost two blue chip sponsors at the end of 2010 - Dutch electronics company Philips and troubled bank Royal Bank of Scotland. However the team listed on the Frankfurt stock exschange in March 2011 and gained Venezuelan state oil company PDVSA with driver Pastor Maldonado. It has also built a relationship with the state of Qatar, where it has a technology centre and is hoping for more partners.A team source said the AT&T deal had not been "sustainable" Williams was now advanced in negotiations with another telecom company for the title sponsorship. No details were given.The team also has to select a second driver for 2012; the first race will be the Australian GP in Melbourne on March 18. Brazilian Rubens Barrichello is hoping to be kept on for his 20th F1 season but has strong competition from Germany's Adrian Sutil.Russian Vitaly Petrov and Brazilian Bruno Senna are also looking for seats after being dropped by Renault, which will race in 2012 as Lotus.