Haggling over liabilities is holding up an otherwise done deal between BASF and the private equity owners of Cognis, several sources told Reuters.

Talks over the sale of the additives maker Cognis are in the final stage, people familiar with the procedure said on Wednesday, with one of them adding an agreement this month is very likely.

Separately, global chemicals market leader BASF unveiled plans to boost sales more than 75% by 2020, saying takeovers remain an important part of growth. Permira and Goldman Sachs Capital Partners, which control Cognis, are keen to pass along to the new owner all risks associated with the chemical company, including pension liabilities. Permira, Goldman Sachs and BASF declined to comment.

With no rival suitors left, the chief executive of BASF is said to be negotiating hard to get a price discount for whatever liability BASF agrees to take. Juergen Hambrecht's term as BASF CEO expires in one year and a person familiar with his thinking said he is determined not to leave unforeseeable burdens with BASF, the world's largest chemicals maker.

Investors have rapped Hambrecht for the €3.1 billion ($3.79 billion) BASF paid for Swiss peer Ciba in a deal announced during the height of the financial crisis in September 2008. Cognis's price tag is set to be above €3 billion - including €1.9 billion in net debt - but the final price is still being negotiated, sources said.

Financial Times Deutschland earlier reported BASF and Cognis' owners had come to terms on the price and on the main conditions of the deal, citing people familiar with the talks. Cognis's Chief Financial Officer Marco Panichi, citing prevailing core earnings multiples in the industry, indicated last month that a fair value for Cognis could be about €3.4 billion ($4.2 billion), according to Reuters calculations.

Sources told Reuters earlier this year that U.S. specialty chemicals maker Lubrizol and at least one other company had also been interested in Cognis, but sources have recently said BASF has become a clear frontrunner in the auction.

Cognis makes additives for cosmetics and detergents and its specialty is using raw materials from palm trees, coconut and corn. These products would sell well through BASF's existing marketing channels and a takeover would also be a timely bet on a recovery in consumer goods markets, analysts have said.

Speaking to investors in New York on Wednesday, BASF CEO Hambrecht said annual sales should grow to more than €90 billion by 2020, mainly expanding its core chemicals operations and "repositioning" its oil and gas business. He also reiterated that BASF should retain 18% of sales as core earnings by 2012, a margin the company last surpassed in 2006. Core earnings were 14.6% of sales in 2009 and 17% in the first quarter 2010.