By Anna Driver

HOUSTON (Reuters) - ConocoPhillips <COP.N> will divulge more details on Wednesday about its plan to split into two companies, with its chemical joint venture, Canadian oil sands assets and pipelines likely the focus, analysts said.

Details are expected to come from Chief Executive Jim Mulva's scheduled remarks at the Barclays CEO Energy-Power conference in New York Wednesday morning.

In July, ConocoPhillips sketched out a plan to spin off its refining arm as part of its ongoing effort to boost shareholder value. At that time, the company remained mum about where some assets would go, either to the refining arm or the exploration and production company. Now, more details are expected.

Marathon Oil Corp <MRO.N>, a much smaller competitor, announced a similar plan to split. But Conoco, unlike Marathon, has a maze of joint-venture deals with other companies, thousands of miles of pipeline and sophisticated assets that make its split strategy more complicated, analysts said.

"I think we won't see as clear a break up as we did with Marathon," Allen Good, analyst with Morningstar, said. "They may have to get more creative with their joint-venture partnerships."

For example ConocoPhillips has partnerships with Canada's Cenovus Energy Inc. <CVE.TO>. The partners have Foster Creek and Christina Lake producing assets was well as two U.S. refineries.

Foster Creek and Christina Lake are expected to stay with Conoco's exploration and production business, the company and analysts have said, but the fate of the refineries is less clear, analysts said.

A representative from Cenovus was not immediately able to comment.

Analysts at Simmons & Co International, a Houston-based energy investment bank, said the company's exploration and production business will likely focus on five regions --Alaska, the lower 48 U.S. states, Canada, North Sea and Asia Pacific.

Simmons also said it expects DCP Midstream Partners <DPM.N>, Conoco's oil and natural gas gathering and processing venture with Spectra Energy <SE.N>, and Chevron Phillips, Conoco's chemical joint venture with Chevron Corp <CVX.N>, to end up with the refining arm.

Others see parts of the DCP business fitting with both arms of the company.

"The problem with DCP is that some of the assets fit with upstream," said Phil Weiss, oil analyst at Argus. "And it's got some pipeline assets that really fit with the downstream. Maybe in the interim they do a services agreement."

Shares of Conoco fell $1.02, or 1.5 percent, to $65.42 in afternoon New York Stock Exchange trading.

(Editing by Steve Orlofsky)