India's Reliance Industries is boosting crude imports from Africa and cutting its dependence on the Middle East as the owner of the world's biggest refining complex seeks to benefit from shifting global oil flows caused by the US shale boom.

African and Latin American crude, which at present account for about 56% of Reliance's imports, have become cheaper as the US slows purchases and increasingly turns to domestic shale oil, while Middle Eastern heavy crude grades are pricier due to demand from regional refinery expansions.

Reliance is making the switch as it wants to cut its crude costs to stem a decline in its refining margins that hit a four-year low of $8.1 a barrel in 2013-14.

While Reliance does not disclose its detailed crude imports, tanker arrival data obtained by news agencies from trade sources shows that its purchases from Africa in the first four months of 2014 rose 5% from a year ago to about 142,800 barrels per day (b/d), making up 12% of its overall imports.

Over the same period, the Indian company's imports from the Middle East fell 1.4% to about 483,800 b/d and the share of Middle Eastern grades in imports declined to 40.7 %. On a full-year basis, this would be the lowest in at least eight years.

The front-month Brent-Dubai price spread, also known as Exchange for Swaps has softened over the past year and now averages near $4 a barrel, making African oil attractive at a time when freight rates have fallen.

Controlled by Billionaire Mukesh Ambani, Reliance operates two refineries at Jamnagar in western India that can process 1.2 million b/d of cheaper heavy-sour crude and export fuel.