MEXICO CITY, March 27 (Reuters) - Mexican national oil company Pemex plans to operate at least two new blocks it won with partners in a shallow water auction on Tuesday, the company's exploration chief said in an interview.

The company expects overall investment of as much as $300 million in the four-year exploration phase of the seven contracts it won, more than any other firm, said Jose Antonio Escalera, Pemex's longtime head of exploration. (Reporting by David Alire Garcia and Marianna Parraga; Editing by Dave Graham)