* Around 2.1 mln bpd set load in April (1.86 mln in March)
* 14 of 17 crude oil streams show rising trend in exports
* Maintenance work at key oilfields due to be completed
(Updates detail from production streams; paragraphs 3-4)
By Christopher Johnson
LONDON, March 1 (Reuters) - Nigerian crude oil exports are expected to increase sharply in April after several months of lower production due to maintenance at key oilfields, trade and industry sources said on Tuesday.
Nigerian crudes are similar in some respects to Libyan grades and have been attracting strong interest from oil companies unable to load crudes from the North African producer due to the uprising against Libyan leader Muammar Gaddafi, trade sources say.
Initial tanker schedules for 14 of the 17 crude oil production streams in Nigeria show 61.0 million barrels, or 2.03 million barrels per day (bpd), of crude are due to load in April in 68 full or part cargoes.
Data from the remaining streams are not yet available, but if the exports for those areas are similar to recent averages, Nigeria's total exports would be close to 63.7 million barrels, or around 2.1 million bpd in 71 full or part cargoes.
That would take sales from Nigeria, Africa's biggest oil exporter and a key member of the Organization of the Petroleum Exporting Countries, back to levels not seen since January.
Nigeria is scheduled to load around 1.86 million bpd in March in 65 cargoes, revised loading programmes show.
Nigeria has an implied OPEC oil production target of 1.67 million bpd but has not been inside that level for around two years, trade and industry figures suggest.
Many of Nigeria's crude oil grades are light and of relatively high quality, with a low percentage of corrosive sulphur compounds, making them attractive to refineries.
Unrest in Libya has cut its oil output by half, the chief economist of the International Energy Agency has said, and many traders have looked to Nigeria as a possible alternative supply, sending premiums for Nigerian crudes up sharply.
Repairs to several key Nigerian oilfields are continuing but should be completed later this month, industry sources say.
Royal Dutch Shell (RDSa.L: Quote) has been carrying out maintenance at its deep offshore Bonga oilfield, reducing output to just 32,000 bpd this month from around 184,000 bpd in January, industry sources say. Production will recover to 133,000 bpd in April, loading schedules show.
Output from Nigeria's biggest benchmark crude oil stream, Qua Iboe, will also increase in April after maintenance, rising to around 412,000 bpd from 337,000 bpd in March and 305,000 bpd in February, the programmes show.
State producer Nigerian National Petroleum Corp. (NNPC) has said it is producing no more than its OPEC output target and that the country's combined crude and condensate production was currently 2.4 million bpd. It has given no breakdown or details.
Nigeria produces significant amounts of condensate, a very light hydrocarbon, which is excluded from the crude export totals and from its OPEC output target.
Loading schedules suggest condensate output is also increasing with five 950,000-barrel cargoes of Akpo condensate due to load in April, up from four in March. (Reporting by Christopher Johnson; editing by Jane Baird)