Chemicals company Clariant has agreed to sell three units to U.S. private equity firm SK Capital for 502 million Swiss francs ($550 million) in a boost to plans to move away from low-margin cyclical businesses.

Clariant had put its textile chemicals, paper speciality chemicals and emulsions units up for sale earlier this year to reduce its exposure to areas of the market vulnerable to swings in the global economy.

The sale has happened more quickly than expected, giving a boost to Clariant's shares, which rose more than 4%.

"For Clariant the transaction marks a significant milestone in the execution of its profitable growth strategy, after the acquisition of Sued-Chemie in 2011," Chief Executive Hariolf Kottmann said in a statement on Thursday.

In October, Clariant had had to cut its full-year sales forecast, showing the impact of Europe's economic slowdown. The chemical industry's dependence on highly cyclical machinery makers, car manufacturers and builders makes it especially vulnerable to economic downturns.

The company is still reviewing its leather services, detergents and intermediates businesses as part of a wider restructuring to meet certain financial goals by 2015.

These revamp plans followed the Basel-based chemicals firm's acquisition last year of German group Sued-Chemie, which provides access to high-growth sectors such as the petrochemical industry in the Middle East.

Sued-Chemie's catalysts unit, for example, makes compounds to speed up chemical reactions and also help turn plant material into biofuel.

Analysts at Bank Vontobel, Barclays Capital and Berenberg welcomed the outright sale as opposed to a partnering deal. They also said the sale had come earlier than expected.

"Despite short-term economic headwinds, such as guidance lowered with Q3 results, today's level represents a clear buying opportunity from a risk-reward perspective," Bank Vontobel analyst Patrick Rafaisz said.

He said Clariant shares offered above peer group average earnings-per-share growth prospects.

The businesses sold had around 1.2 billion francs in 2012 sales, or roughly 15% of the firm's total revenue. Clariant will receive 460 million francs in cash from the sale.