(Adds vessel bookings data through early July, analyst comment)
MEXICO CITY, July 8 (Reuters) - Mexican state-owned oil company Pemex is ramping up gasoline imports and boosting domestic production at two major refineries after fuel shortages led to long lines at gas stations in several states this week.
Pemex announced on Monday an "extraordinary" gasoline import surge of 75,000 barrels per day (bpd), which company data showed was in addition to gasoline imports that totaled 370,000 bpd in May.
P.M.I. Comercio Internacional, Pemex's commercial arm, has already booked just over 1 million tonnes of oil product imports in June and through the first week of July, up from imports of about 410,000 tonnes during both months last year, according to vessel booking data from Thomson Reuters Eikon.
More than half of Mexico's fuel imports in recent months have been gasoline.
"They came into the market at a bad time," said Robert Campbell, head of oil products research with Energy Aspects, referring to Pemex's buying spree.
Ultra-strong gasoline demand worldwide, from the United States to India, has soaked up much of the world's excess supply. Additionally, problems at gasoline-making fluid catalytic crackers in Venezuela and the United States have tightened availability and created more rival buyers.
Since Monday, Pemex has not responded to requests for more information.
Pemex has blamed the shortage on an increase in illegal taps on gasoline pipelines, a long-standing problem but one that is on pace to set a record this year.
Pemex said in a statement on Monday that the number of illegal taps so far this year has reached 2,813, already two-thirds of the year-end figure last year.
Francisco Fuentes, Pemex's deputy director of storage and distribution, told broadcaster Televisa on Monday that the theft is particularly bad at pipelines near two main refineries, Salamanca and Cadereyta.
The refineries supply much of the fuel needs of Mexico's second- and third-biggest cites, Guadalajara and Monterrey, where gas station lines have been most visible.
The company also said it has finished maintenance at its Salamanca refinery in central Guanajuato state which will allow fuel output to grow by 42,000 bpd.
Meanwhile, maintenance at the Cadereyta refinery, in northern Nuevo Leon state, is set to wrap up next week, which would allow the plant to ramp up fuel output of some 85,000 bpd. (Reporting by David Alire Garcia and Ana Isabel Martinez in Mexico City and Libby George in London; Editing by Matthew Lewis)