By Emma Farge and Joe Brock LONDON (Reuters) - Nigeria's crude oil exports are set to top 2 million barrels per day (bpd) for the third month running in September, trade sources said on Wednesday, as Africa's largest energy producer improves output reliability. Nigeria will export an average of 2.10 million bpd of crude oil in September, up slightly from a revised 2.08 million bpd in August, according to data from oil companies and traders. Preliminary loading programmes showed that 71 full or part cargoes are due to be shipped in September, little changed from the 70 planned in the longer month of August. Crude oil production from the OPEC member has stabilised since an amnesty programme for militants in the oil-producing Niger Delta region resulted in a year without significant attacks on facilities. Production hit multi-year highs above 2.2 million bpd in July, but some minor technical problems are expected to trim output in August and September. ExxonMobil, operator of the Qua Iboe stream, declared force majeure on exports of Nigeria's benchmark crude due to pipeline damage in May this year, leading to a reduction in output in June and July. But repair works look to have recaptured some of the lost production. Loading programmes showed that September Qua Iboe output will average around 318,000 bpd, up from around 275,000 bpd the previous month but still down from 2010 highs of more than 380,000 bpd reached in May. Elsewhere, six cargoes of Bonny Light and five cargoes each of Escravos, Bonga and Erha are due to load in September, the programmes showed. Nigeria will again far exceed its crude production target agreed with the Organization of the Petroleum Exporting Countries, which has been set at 1.67 million bpd, trade sources said. OPEC agreed on output curbs in 2008 to support falling oil prices, which dropped from a high of nearly $150 a barrel in July 2008 to below $33 in December the same year. With U.S. crude oil trading mostly between $70 and $80 per barrel, OPEC members have said they are happy and that there is little incentive to adhere to output targets.