FRANKFURT, June 2 (Reuters) - BASF (BASF.DE) has agreed in principle with the private equity owners of Cognis [COGN.UL] on a takeover of the German maker of additives, a newspaper reported on Wednesday 2 June.

BASF, the world's largest chemicals maker, and Cognis's owners Permira [PERM.UL] and Goldman Sachs Capital Partners (GS.N) have agreed terms on the price and on the main conditions of the deal, Financial Times Deutschland (FTD) said, citing people familiar with the talks.

However, an official announcement should not be expected before mid-June because BASF plans to carry out final checks as part of a "confirmatory due diligence", the paper added.

FTD said it could not ascertain the agreed acquisition price for the maker of chemicals for cosmetics and detergents.

Permira and Goldman Sachs declined to comment on Wednesday 2 June. Officials at BASF were not immediately available.

Cognis's CFO 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 euros ($4.2 billion), according to Reuters calculations.

Cognis's private equity owners relaunched their campaign to sell the company outright as it prepared to go public.

One person familiar with the matter said this month that offers had been more than 3 billion euros but less than 3.5 billion euros ($3.8 billion to $4.5 billion), including assumed debt.

Sources told Reuters earlier this year that U.S. specialty chemicals maker Lubrizol (LZ.N) and at least one other company had also been interested in Cognis but sources have recently said BASF had become a clear frontrunner in the auction. (Reporting by Ludwig Burger; Editing by Hans Peters and Erica Billingham)