Reliance Industries, the operator of India's largest oil refinery, has signed a pact with Mexico's national oil company to explore potential upstream oil and gas business opportunities in the Latin American nation.

Reliance and Petroleos Mexicanos (Pemex) will also explore international markets for value added opportunities, the Indian energy giant said in a statement to the Bombay Stock Exchange.

Reliance's stock, India's third-most valuable company with a market capitalisation of over $50bn (£32bn, €40bn), was trading 0.54% higher at 1439 IST in Mumbai while the benchmark BSE Sensex share average was trading flat.

Reliance (RIL), which operates the world's biggest refinery, said the tie-up with Pemex was "in line with its growth strategy to... expand its international asset base in regimes having internationally attractive competitive terms."

"The [memorandum of understanding with Pemex] envisages sharing of RIL's pioneering expertise in deepwater development and best practices [off India's east coast]... and [the firm's] experience in shale gas in [the] United States."

The deal follows energy reforms in Mexico, the world's tenth-largest crude producer, which ended Pemex's decades-long monopoly.

In November, Mexico's energy regulator said it hoped to attract over $50bn in investment through 2018 to check declining crude output. Production in Mexico hovers around 2.35 million barrels per day.

In September, ONGC Videsh, the overseas arm of India's state-run Oil and Natural Gas Corporation, signed an agreement with Pemex to explore opportunities in Mexico's hydrocarbon sector.

In June, Reliance boss Mukesh Ambani, India's richest man, told shareholders that RIL, which has invested more than $7bn on joint ventures in the US, was looking to expand its international footprint beyond the world's leading economy.