Accounting software developer BlackLine is preparing for an initial public offering that could value it at more than $1 billion, according to media reports. An IPO for the Woodland Hills company could come as early as October, Reuters reported Sept. 20, citing unnamed sources familiar with the matter. BlackLine has hired Goldman Sachs to lead the IPO, which has been registered confidentially with the Securities and Exchange Commission, Reuters said. BlackLine was founded in 2001 by Therese Tucker, its chief executive, and develops software that automates the processes of closing out financial books and reconciling accounts to make sure the amount of money coming in matches the money being spent. Its existing customers include Dow Chemical Co., Coca-Cola Co. and Air Medical Group Holdings. The last company to go public in the San Fernando Valley was Sylmar-based Second Sight Medical Products Inc. in November 2014.