Russian state-controlled oil giant Rosneft may take out loans from Western banks, sell non-core assets and bond issues to finance the purchase of TNK-BP, Rosneft head Igor Sechin said on Monday.

Rosneft announced on Monday it had reached agreement with British oil major BP to acquire its 50 percent interest in TNK-BP in exchange for $17.1 billion in cash and 12.84 percent Rosneft shares currently held in treasury.

In a similar deal, Rosneft agreed to repurchase the remaining 50 percent stake in TNK-BP from the AAR consortium of Russian billionaire shareholders “for cash consideration of $28 billion.”

 “There is a possibility to close the deal completely using funds raised from Western banks. The money on the accounts [of Rosneft] will also be used; the option of selling non-core assets is under discussion and there is a program to float bonds,” Sechin said.

Sechin previously said the deal to buy all of TNK-BP was worth $61 billion.

Rosneft’s credit rating is unlikely to fall despite the sizable loans the company intends to take on, and eventually the company should even be able to improve its financial and economic performance, Sechin said.

Rosneft has passed the documents relating to the purchase of BP’s 50 percent stake in Russia’s third largest oil producer TNK-BP to the Russian government for approval, he said.

“We have sent the deal to the government and federal agencies for approval as per the established procedure,” Sechin said.

Rosneft may consolidate 100 percent of TNK-BP’s shares within six months, he said.

“With intense work, we have the opportunity to close the deal within six months.”

Rosneft’s deal for the all-out purchase of TNK-BP would make it the world’s largest publicly traded oil company, with higher crude production than global energy titans Exxon Mobil and Royal Dutch Shell.

The deal would also allow Rosneft to boost annual oil production to 200 million metric tons (4 million barrels per day), Sechin said, adding the company would not turn into a monopoly on the domestic market as it would account for less than half of all oil produced in the country.

“We don’t have a monopoly position and there is nothing to discuss on this score,” he said.