Online grocery store HomeGrocer.com is to lay off 100 employees at its Washington headquarters in addition to the 50 people made redundant in September.More layoffs are expected as the company is integrated into former rival Webvan, which completed a $1bn acquisition of HomeGrocer.com three months ago. HomeGrocer now employees about 300 people. California-based Webvan has been having problems of its own. The company's current market capitalisation is $156m and shares are trading well below $1. At IPO just over a year ago, the company was worth $6bn.