LAGOS- Judges in Lagos have blocked Nigeria's efforts to revoke two oilfield licences, court documents seen by Reuters showed, a move that could compromise a full licensing round for marginal fields which the government is aiming to launch as early as this month.

Marginal fields are smaller oil blocks that are typically developed by indigenous companies. Nigeria had revoked the licences so these fields could go into the new licensing round - the first marginal field round since 2002 - which the country hopes will boost oil output and bring in much-needed revenues from fees associated with the licences.

The Ororo field, OML 95, and the Dawes Island Marginal Oil Field, formerly called OML 54, were among 11 licences revoked by the Department of Petroleum Resources in April.

All 11 were set to be included in a total of 56 fields in the marginal field licensing round.

Two different judges in Lagos granted decisions on May 27 that halt the inclusion of the two fields in any licensing round, the court documents seen by Reuters showed.

Potential legal challenges relating to the other licences revoked in April mean that all of the 11 licences could potentially be left out of the round, two sources familiar with the matter said.

The DPR said it could not comment on a matter that was ongoing before the court. The Ministry of Petroleum Resources did not immediately comment on the rulings.

Owena Oil and Gas Ltd, said in its lawsuit that the DPR revoked its OML 95 licence "without recourse to the plaintiff," court documents seen by Reuters showed. Eurafric Energy Ltd. challenged the revocation of Dawes Island and said it had spent money developing the asset, the court documents showed.

Owena Oil and Eurafric Energy were not immediately reachable for comment.

Nigeria said last month it would delay major licensing rounds due to coronavirus disruptions, more than halving its projected revenue from signature bonuses to 350 billion naira ($972.22 million) from 939 billion naira originally expected. But it planned to accelerate the licensing rounds for marginal fields.

Nigeria has not held a major licensing round since 2005.

(Reporting By Libby George. Editing by Jane Merriman) ((Libby.George@thomsonreuters.com; +234 809 065 5059 ; Reuters Messaging: libby.george@thomsonreuters.com))