* Qua Iboe said sold at dtd plus $1.15-$1.20, down 5-10 cts

* Nigerian Nov programmes may be 1.87 mln bpd (1.80 in Oct)

* November programmes emerging: 5 Erha, 3 Antan, 3 Okwori

LONDON, Sept 25 (Reuters) - Nigerian crude oil differentials slipped further on Friday with benchmark Qua Iboe reported sold at around 50 cents below its official selling price (OSP) for October, traders said.

Preliminary indications suggested the Nigerian loading schedule for November could be well above the programme for October with as much as 1.87 million barrels per day (bpd), up from 1.80 million bpd in October but down from 1.95 million bpd in September.

This would make the Nigerian programme bigger than the loading schedule for Angola for the first time in several months. Angola is expected to export around 1.82 million bpd in November.