Barclays is nursing a double-digit percentage decline after news that International Petroleum Investment Company (IPIC) is selling 1.3bn of the UK bank's shares.Credit Suisse is reported to have placed the shares at around 267p, equivalent to £3.5bn. Khadem Al Qubaisi, managing director of IPIC, said that the sale did not represent a lack of faith in Barclays, its management or current strategy.Barclays said it hopes to expand its strategic and commercial relationship with the IPIC despite IPIC's decision to reduce its stake in the UK bank.IPIC continues to hold warrants convertible into a further 758m Barclays shares exercisable at a price of 197.775p per share."In the period since IPIC and the government of Abu Dhabi took a position in Barclays in 2008 through their purchase of MCNs and RCIs we have been able to broaden our strategic and commercial relationship, and we look forward to developing this further going forward," said Barclays chief executive, John Varley."The decision to dispose of some of its interests in Barclays reflects the focus of IPIC's long-term investment strategy on hydrocarbon-related opportunities," said HE Khadem Al Qubaisi, managing director of IPIC.