Adecco Group AG said Wednesday that it swung to profit for the fourth quarter, but that revenue declined on year.

The Swiss human-resource company said net profit was 256 million euros ($277.4 million), from a loss of EUR112 million in the year-earlier period.

Revenue fell 4% on an organic basis to EUR5.96 billion, the company said. In January, revenue was down 5% on year, with volumes in February pointing to a similar trend.

Adecco said it would propose a dividend of 2.50 Swiss francs ($2.55) a share for 2019. It also announced a share-buyback program of up to EUR600 million for the 2020-21 period.

Looking ahead, the company said it expects a slowdown due to continued uncertainty in the global economy and potential disruptions to manufacturing supply chains in relation to the coronavirus outbreak in Asia.

For 2020, Adecco targets an underlying improvement in the earnings before interest, taxes and amortization margin and said it is on track to deliver its savings target of EUR250 million in 2020.

Write to Giulia Petroni at giulia.petroni@wsj.com