UPDATE 1-BP Texas City FCC still running -sources

(Adds FCC still running, BP no comment, combines urgents)

HOUSTON Feb 19 (Reuters) - A gasoline-producing fluidic catalytic cracking unit at BP Plc's (BP.L) (BP.N) 455,790 barrel-per-day (bpd) Texas City, Texas, refinery continued operating on Friday.

The FCC was running despite a leak causing excess ammonia pollution, according to sources familiar with refinery operations.

A BP spokesman declined to discuss refinery operations.

In a notice filed with Texas pollution regulators, BP said, a leaking regulator was causing increased flow of ammonia from FCC No. 1 through its electrostatic precipitator, which collects particulate matter.

To correct the problem, BP was reducing flow to the regulator on Friday so it could make repairs, according to the notice filed with the Texas Commission on Environmental Quality.

It was unclear if production on the FCC was also reduced. (Reporting by Erwin Seba; Editing by Carole Vaporean)