* Shell says $1 bln/month oil theft figure probably accurate
* Proposed legal changes curbing Nigeria's oil output
* Some Nigerian risks worsened, Shell says in annual report
By Alex Lawler and Simon Falush
LONDON, March 13 (Reuters) - Royal Dutch Shell lostnearly $1 billion through theft and various disruptions to itsNigerian oil and liquefied natural gas (LNG) operations in 2013and said that rampant oil theft is costing the country evenmore.
The Anglo Dutch company, updating investors on its strategy,also said that proposed Nigerian legislation had curbedinvestment, hindering production, while security is a dailychallenge and oil theft "very material".
Nigeria is important for Shell because the African countryprovides almost 10 percent of the company's output and is seenas a source of future growth. In its annual report, alsopublished on Thursday, Shell said that some risks of working inNigeria had worsened.
The Nigerian Petroleum Industry Bill (PIB), a piece oflegislation several years in the making, has not passed but itcould change the terms for foreign oil companies in the country.
"There are at least three to four different versions of itand most of them have been unhelpful to supporting future investments in the country," Simon Henry, Shell's chieffinancial officer, said on a conference call.
PRODUCTION STYMIED
"Therefore the industry at large has taken almost nosignificant investment decision in that six, seven-year period.So the country's 4 millon barrel-a-day target has effectivelybecome actual production of less than 2 (million bpd)."
Nigeria produced about 1.9 million bpd in February,according to OPEC figures.
Oil theft is often associated with criminals who tap crudefrom pipelines for local refining. Stolen oil also leaves thecountry in tankers.
"The theft is very material," Henry said. "Figures have beenquoted up to a billion dollars a month being stolen from thegovernmet, in effect, and that figure is probably accurate."
Shell's Nigerian oil and gas output averaged 265,000 barrelsof oil equivalent per day in 2013, down 100,000 bpd from 2012and equal to about 8 percent of total supply of 3.2 million bpd.
The company, which is in the process of selling some onshoreNigerian oil blocks, still views Nigeria as a source oflonger-term growth and Henry said Shell would continue to investin gas and deepwater projects.