[holding answer 7 April 2010]: HM Revenue and Customs publishes the UK Regional Trade in Goods Statistics, the most recent issue was published on 11 March 2010. A copy can be found at:
https://www.uktradeinfo.com/pagecontent/downloads/RtsPRDataTablesQ409.pdf
These statistics provide data at regional level only so we are unable to confirm the number of exporting companies in the county of Essex or the district of Castle Point.