Essexskipper Mark Pettini declared his side's second innings after Ryan ten Doeschate (56) and Matthew Walker (53no) had both completed half-centuries during the morning session.
BBC: Lancashire wobble but draw with Essex
3.
From 139-5, Essexskipper James Foster struck the ball cleanly and brought up his own half century and his side's 200 with a lofted cover drive off Thomas in the 27th over.
BBC: Marcus Trescothick stars as Somerset see off Essex