US-based Berkshire Hathaway has increased its stake in Occidental Petroleum , Reuters reported, citing a regulatory filing.

The conglomerate purchased an additional 9.6 million shares of Occidental to raise its holding in the oil company to 16.3%.

The latest purchases have a combined value of approximately $529m.

Berkshire now holds nearly 152.7 million Occidental shares. The combined worth of the holding is approximately $8.52bn, as per the latest stock value.

Last month, Berkshire acquired 336 million shares of Occidental.

Berkshire is currently the largest individual shareholder in the oil company. It can exercise options to purchase an additional 83.9 million Occidental shares to increase its stake to more than 25%.

In the first quarter of the year, Berkshire spent nearly $51.1bn on purchasing equities.

Occidental is one of the largest oil producers in the US, with operations in the Permian and DJ basins, and offshore the Gulf of Mexico. The company also has assets in the Middle East and North Africa.

Occidental also has a chemical subsidiary called OxyChem.

For the first quarter of this year, Occidental reported a net income attributable to common stockholders of $4.7bn. In the same period last year, the company registered a net loss of $346m.

Oil and gas pre-tax income on continuing operations in Q1 2022 totalled $2.9bn.

Last month, Occidental and Colombia’s majority state-owned energy company Ecopetrol agreed to jointly explore four offshore, deep-water blocks in the Caribbean.

The deep-waters blocks are located approximately 150km from the coastline of Atlántico, Magdalena, and La Guajira.