LOS ANGELES - Exxon Mobil Corp has suspended offshore production from three drilling platforms along the Santa Barbara, California, coastline following last month’s rupture of a pipeline that carries crude oil away to refineries, the company said on Tuesday. Exxon cited a refusal by Santa Barbara County authorities to approve an emergency application to transport its offshore crude by truck from its onshore processing facility while the crippled line owned by Plains All American Pipeline remains shut down. Current output from Exxon’s shuttered platforms was estimated at about 30,000 barrels per day, a small fraction of California’s daily crude diet of around 1.7 million bpd. Although Exxon’s processing center at Las Flores Canyon has a permitted capacity of 140,000 bpd for crude, its output has been in decline. “We do not anticipate any impact on our employees, and we are exploring a range of options before us as we consider our next steps,” Exxon said in a statement announcing it was temporarily ceasing production at its Hondo, Harmony and Heritage platforms in the Santa Barbara Channel. County energy officials were not immediately available to comment on Exxon’s move. The 24-inch Plains pipeline has been shut down since it burst, belching as much as 2,400 barrels (100,000 gallons) of crude onto a pristine stretch of shoreline and into the Pacific. The oil spill ranks as the biggest to hit the ecologically sensitive Santa Barbara coast northwest of Los Angeles in more than four decades. The crippled pipeline, when operating, carries processed crude from Las Flores to a pumping station, where the petroleum flows into a larger line that transports it to a distribution hub in Bakersfield and on to refineries hundreds of miles away. The Plains line also carries away processed crude oil from the Holly platform operated in the channel by privately owned Venoco Inc, which previously halted production of that rig following the pipeline spill.