The latest twists in the Occidental-Chevron battle for Anadarko

Last night Occidental Petroleum sweetened its offer to trump Chevron's plan to purchase Anadarko Petroleum.

Where it stands: Occidental changed its $76-per-share offer to be 78% cash and 22% stock, compared to the 50-50 split in their prior bid, as they try and snatch Anadarko away from Chevron, a much larger company.

• "Our revised proposal represents a premium of approximately 23.3% to the $61.62 per share value of Chevron’s offer as of Friday’s market close," Occidental said in a letter to Anadarko's board Sunday.
• The letter notes that the revised offer would not require approval from Occidental's shareholders, some of whom oppose the deal.

Why it matters: It's the latest twist in what will be the biggest oil megadeal in years, however it turns out.

• Late last month Occidental said its total offer, including debt, was valued in the $57 billion range based on its share price at the time.
• It shows how powerful oil companies are keen to bolster their holdings in the booming Permian Basin region, where Anadarko has significant acreage.

But, but, but: Anadarko said in a statement last night that they're not ready to switch horses, while pledging to carefully review the revised offer.

• "The Chevron Merger Agreement remains in effect and accordingly the Anadarko board reaffirms its existing recommendation of the transaction with Chevron at this time."

The intrigue: The revised offer arrived just hours after another new wrinkle. Occidental and oil-and-gas behemoth Total announced earlier Sunday that Total would pay $8.8 billion for Anadarko's African assets if the Occidental-Anadarko deal happens.

• Between the lines: This signals how Occidental is seeking to show that it’s well-positioned to emerge from the expensive transaction in a strong position, even though Chevron has much deeper pockets.
• That move arrived just days after Warren Buffett pledged to invest $10 billion to help finance Occidental's takeover bid.

Go deeper: Warren Buffett enters Anadarko bidding war with $10 billion commitment