July 23 (Reuters) - Venezuela's oil ministry has told partners of state energy company PDVSA that it will maintain the July 28 deadline it had set to migrate oil and gas contracts to a new legal framework approved in January, rushing executives to complete the negotiation of terms, three sources close to the talks said.

The migration involves about two dozen foreign and local companies, including U.S. oil major Chevron CVX.N, Spain's Repsol REP.MC and Italy's Eni ENI.MI, most of which have more than one project in partnership or under contract with PDVSA.

Companies getting into Venezuela for the first time - mostly foreign wildcatters and little known firms - do not have a specific deadline to negotiate and agree to contract terms following preliminary agreements signed since early this year, the sources said.

The oil ministry did not immediately reply to a request for comment.