UPDATE 1-Kier says JV gets 250 mln stg contract extension

* Gets deal extension from United Utilities

* Contract extends until March 2015

* Kier shares fall 3.7 pct, Interserve down 2 pct (Adds details)

July 7 (Reuters) - British construction company Kier Group Plc (KIE.L) said on Tuesday its KMI Plus joint venture received a contract extension worth 250 million pounds ($406.8 million) from United Utilities (UU.L) for non-infrastructure work.

KMI Plus joint venture includes Kier Construction Ltd, Murphy Group, Interserve Plc's (IRV.L) Interserve Project Services unit and Mouchel Group (MCHL.L) and the contract extends their association with United Utilities to March 2015, Kier said in a statement.

The venture's Asset Management Programme contract with United Utilities started in 2002 and it had done building, maintenance and refurbishment work for United Utilities.

Kier shares were down 3.7 percent at 862 pence, while Interserve shares were down 2 percent at 175 pence by 1425 GMT on the London Stock Exchange. Mouchel shares were up about 1 percent at 171.25 pence. ($1=.6145 Pound) (Reporting by Purwa Naveen Raman in Bangalore; Editing by Gopakumar Warrier)