U.K. oil major BP PLC (BP) will solely finance the around $2 billion for the first development stages of its joint Arctic project with Russia's OAO Rosneft (ROSN.RS), which will begin drilling in 2015, Rosneft Vice President Peter O'Brien said Monday.

The two companies agreed late last week to form a joint venture to explore three offshore licenses in the
Kara Sea north of Russia . BP will spend up to $2 billion in the initial phase on seismic testing and drilling wells.

The deal also includes a share swap, which will give Rosneft a 5% stake in BP, while BP will get a 9.5% stake in Rosneft.

The three
Arctic blocks EPNZ 1, 2, 3, which are roughly equivalent in size and reserves to U.K. 's North Sea fields, primarily hold natural gas. However, the partners will mainly focus on the oil deposits and only develop the natural gas at a later stage, said O'Brien.

A BP spokesman said the first drilling could happen in 2015 at the earliest, but is likely to be later than that. BP will host a conference call later Monday.

O'Brien also said the two companies still have to discuss the possibility of joint representation on their respective boards, as part of the share swap.