Royal Dutch/Shell Group's efforts to revive flagging profit gathered speed as the company, based in London and The Hague, streamlined top management, while separately agreeing to sell a piece of its chemicals business. The moves by the world's top publicly traded oil company come ahead of a Monday meeting in which analysts expect the company to take $5 billion in charges to write down assets that Shell already has under review to be sold or closed. Shell, which is naming chief executives for its two largest businesses, is slimming staff and removing parts of the leadership-by-consensus model adopted in the 1950s. The steps are part of Shell's plan to cope with plunging oil prices. Shell also faces rising pressure from Exxon Corp. and British Petroleum Co., which plan multibillion-dollar mergers to form companies that rival Shell's size. In the chemicals unit, Shell said it was in advanced talks to sell its 50% stake in Wavin, Europe's biggest maker of plastic pipe, to CVC Capital Partners. The unit, with annual sales of $910 million, is a small step in Shell's plan to trim its chemicals division.