UPDATE 1-Cello Group H1 like-for-like gross profit down

* Sees meeting market view for FY headline oper profit * Says H1 oper margins squeezed

* H1 like-for-like professional costs cut by 7 pct

* Sees one-time charge of 0.4 mln stg in H1

* Shares fall 11 pct

July 3 (Reuters) - British research and consulting firm Cello Group Plc (CLL.L) said on Friday its first-half like-for-like gross profit fell 10 percent, and operating margins were also squeezed, due to slower client activity.

Cello shares were down 11 percent at 33.5 pence by 0707 GMT on the London Stock Exchange.

However, the company, which carries out direct marketing campaigns and user satisfaction surveys, said it expects to meet market estimates for full-year headline operating profit, helped by good contract retention.

The company said weakness in qualitative research was offset by its focus on pharmaceutical, international and public sector research.

Cello, which continued to take measures to cut costs, said like-for-like professional costs were reduced by about 7 percent.