Malaysian prime minister Malaysian Prime Minister Datuk Seri Mohd Najib Tun Haji Abdul Razak is to pay a working visit to Brunei Darussalam , tomorrow, Sunday during which he , and Hassanal Bolkiah, Sultan of Brunei co-chair the 17th annual negotiations between the two countries. The Malaysian Foreign Ministry said in a press release issued here Saturday that the two sides will sign a set of cooperation agreements in the hydrocarbons and development of cooperation societies and other areas.