KIEV, April 6 - Ukraine’s biggest producer of large-diameter steel pipes used for oil and natural gas pipelines, Khartsyzsk Pipe Plant, increased pipe output to 11,893 metric tons in March from 353 mt produced in February, the company reported Tuesday.

Khartsyzsk Pipe Plant produced 31,120 mt of pipes in the first quarter, down from 149,810 mt produced in January-March 2009.