ALASTAIR Cook and Tom Westley continued their prolific form as Specsavers County Championship Division Two leaders Essex enjoyed another successful day despite being held up by the weather against Worcestershire at ew Road.

England Test captain Cook, who has already scored two centuries this season against Gloucestershire and Sussex, completed a sedate fifty off 112 balls with seven fours and a six.

Westley was the more aggressive, reaching his half century off 64 balls and this is the sixth successive first class match in which he has topped 50 starting with his appearance for the MCC against Yorkshire in Abu Dhabi in March.

The unbroken stand of 128 in 37 overs fully justified Essex skipper Ryan ten Doeschate's decision to bat first after winning the toss.

But rain and bad light meant only 40 overs were possible in two spells after the loss of the afternoon session as Essex closed on 144 for one.

Cook was unbeaten on 53 and Westley was 70 not out when umpires Neil Mallender and Michael Burns called off play for the day.

Worcestershire paceman Matt Henry claimed the only wicket to fall. The New Zealander marked his home debut by having Nick Browne (15) caught behind by keeper Ben Cox with 16 on the board.

But generally after that bat dominated ball and Westley signalled his intent with successive cover drives for four at Henry's expense.

Cook had one slice of good fortune when he edged Joe Leach for four to bring up the Essex half century in the 10th over.

But he produced a far more authoritative stroke when lofting his England team-mate Moeen Ali over mid on for six.

Cook's only other real scare was on 33 when he went for a risky single off Jack Shantry to mid on and may have been struggling to make his ground had Henry's throw hit the stumps.

Essex reached 105 for one in 24.1 overs when rain started to fall at 12.30 and prompted a delay of more than four overs.

The players re-appeared at 4.40pm with a possible 29.5 overs remaining and Westley had a slice of good fortune when he inside edged Ed Barnard for four to reach his 50 before lofting the same bowler over square leg for six.

Cook pulled Shantry for four to complete his 50 shortly before the players left the field for the final time at 5.35pm.

Skipper Daryl Mitchell used five bowlers in a bid to make further breakthroughs but Cook and Westley stood firm.

Worcestershire were at least happy to stage some cricket at their headquarters after the complete wash-out of the opening clash with Kent.