* Carson refinery work could last through March 12
* Work was expected to last six weeks, finish Feb. 22 (Adds BP no comment, background)
HOUSTON, March 1 (Reuters) - BP Plc's 240,000barrel-per-day (bpd) Los Angeles-area refinery in Carson,California, extended by four days the time needed to complete anoverhaul on the 102,500 bpd gasoline-producing fluidic catalyticcracking unit, said sources familiar with refinery operations onFriday.
The refinery filed a notice with California pollutionregulators that planned flaring at the refinery was possiblethrough March 12. Previously, BP had warned of planned flaringat the refinery through March 8.
Both of the notices were due to flaring needed as work iscompleted on the FCC and a related alkylation unit, the sourcessaid. A refinery engages its safety flare system when it cannotprocess hydrocarbons normally due to a malfunction or plannedmaintenance.
A BP spokesman declined to discuss operations at therefinery.
The FCC and alky unit overhaul had been expected to finishafter six weeks on Feb. 22, but more work was needed on the FCCthan had been anticipated, extending the overhaul, the sourcessaid.
An alkylation unit converts refining by-products intooctane-boosting additives for gasoline. (Reporting by Erwin Seba; Editing by Gerald E. McCormick andBob Burgdorfer)