San Francisco--Charles Schwab & Co. unit Schwab Institutional will begin offering after-hours trading to its financial adviser firm clients. The company will also market the service, which will roll out next month, on its Web site (www.schwab.com). The program will allow financial advisers to trade Nasdaq-listed stocks between 4:30 and 7:00 p.m. "A large portion of our customer base is on the West Coast. For years, they've watched the markets close during lunchtime. Now we're going to give them the opportunity to trade throughout the business day," co-CEO Charles Schwab said in a statement.