LONDON, Jan 9 (Reuters) - Nigeria's state oil company NNPC has allocated four crude cargoes from its February programme to the $20 billion Dangote refinery, which is poised to begin operations after years of construction delays, three sources with direct knowledge of the matter told Reuters.

What will be Africa's biggest refinery has said it could begin test runs as early as this week, adding that it has received six initial crude cargoes.

It received 1 million barrels of Nigeria's Agbami crude on Monday, lifting total volumes received since December to 6 million barrels.

NNPC supplied the 650,000 barrel per day (bpd) plant with four of the cargoes, two of the sources said.

A spokesperson for NNPC declined to comment and Dangote did not reply immediately to a request for comment.

One of the sources said that the refinery did not request additional crude cargoes from NNPC for January but has nominated four for February.

The second source said that NNPC wanted to wait for the plant's test runs before sending more oil.

Initial processing capacity is expected to reach 350,000 bpd, with the aim of ramping up to full capacity by the end of the year, Dangote said.

OPEC member Nigeria currently relies on imports for most of the fuel it consumes, but the Dangote refinery is expected to make it self-sufficient and able to export fuel to neighbours in West Africa, potentially transforming oil trading in the Atlantic Basin. (Reporting by Ahmad Ghaddar and Libby George in London and Julia Payne in Brussels Additional reporting by Chijioke Ohuocha and Camillus Eboh in Nigeria Editing by David Goodman)