Exclusive - Mexico energy reform won't offer private oil concessions - ruling party head

MEXICO CITY (Reuters) - A sweeping energy overhaul that Mexican President Enrique Pena Nieto is set to unveil on Monday will not offer private oil companies concessions to tap Mexican oil, but will propose to amend the constitution to allow them to invest in the ailing sector, the head of the ruling party told Reuters on Sunday.

The energy overhaul is the cornerstone of a wide-reaching reform package that Pena Nieto hopes will boost economic growth in Latin America's No. 2 economy and lift Mexico's energy sector into the modern era.