BUZZ-Serco: shares briefly halted as stock dives to 11-year lows
** Serco under renewed pressure as Credit Suisse (NYSE: CS - news) cuts its rating on stock to "underperform" vs "neutral"
** Shares (Frankfurt: DI6.F - news) down 10.1 pct, entering 5 minute auction period at 0924 GMT, top faller on FTSE 250
** Busiest UK midcap stock with more than its normal 90-day daily average traded after around an hour
** Serco now down some 50 pct since last week when group wrote off value of operations by 1.5 bln pounds & said it would turn to investors for emergency cash to rebuild firm
** Credit Suisse reckons Serco is too expensive on a look-through basis; it estimates the shares to be trading on 27 times fully diluted 2016 PE
** Broker says that after the unveiling of significant onerous contract provisions & risk of more to come, it sees huge uncertainty around co's operational cash flows (RM (LSE: RM.L - news) : tricia.wright1.thomsonreuters.com@reuters.net)