By Joe Hoppe

The U.K.'s markets regulator said Thursday that it has served an initial enforcement order on National Grid PLC, relating to its expected acquisition of Western Power Distribution.

The Competition and Markets Authority said that it served the order on June 9, preventing the full integration of National Grid and WPD.

National Grid had said on March 18 it was looking to buy WPD from PPL Corp. for an equity value of 7.8 billion pounds ($11.01 billion).

WPD owns four distribution networks in the U.K., delivering power to around 7.9 million customers. The acquisition was expected to complete around July.

Write to Joe Hoppe at joseph.hoppe@wsj.com

Corrections & Amplifications

This item was corrected at 0750 GMT to reflect that the Competition and Markets Authority said that it served the initial enforcement order on June 9. The original version incorrectly said the order had been issued on May 17 in the second paragraph.

(END) Dow Jones Newswires

06-10-21 0244ET