OSLO/COPENHAGEN, Dec 20 (Reuters) - Insurer Storebrand has agreed to buy the Norwegian unit of Danish pension provider Danica from Danske Bank, the companies said on Monday.

Norway's Storebrand will pay 2.01 billion Norwegian crowns ($221.4 million) for Danica Pensjonsforsikring AS, the sixth-largest provider of defined contribution pensions in Norway, with a 5% market share.

"With Danica on board, we strengthen our presence in the occupational pensions market for small and medium-sized enterprises and our personal risk offering," Storebrand Chief Executive Odd Arild Grefstad said.

Danske Bank expects a one-off gain of 400 million Danish crowns ($60.5 million) from the deal to sell the Danica unit, which manages assets worth 30.4 billion Norwegian crowns and earned a pretax profit of 127 million Norwegian crowns in 2020.

Brokers Nordnet said in a note to clients that Danske's Norwegian operations lacked sufficient scale and that the bank's return on equity would improve if it sold out of Norway altogether.

Danske rejected the idea of a full retreat, however.

"We have been a player on the Norwegian market for 150 years, and the Norwegian market will remain important to Danske Bank," said Glenn Soderholm, Danske's head of personal and business customers and chair of Danica's board.

"However, the sale of the Norwegian part of the pension business at an attractive price represents a very good opportunity for us to execute on our strategy to simplify and strengthen our business," he added.

The acquisition will not affect Storebrand's ability to pay dividends for 2021 and is expected to improve its return on equity as well as its capacity for payouts to shareholders in the longer term, the Norwegian company said.

The deal is expected to close in the first half of 2022.

Danske Bank's shares were down 2.5% at 0915 GMT while Storebrand's were down 2.6%, in line with a 2.6% retreat in European banking stocks as global markets tumbled on fears of the Omicron variant.

($1 = 9.0780 Norwegian crowns; $1 = 6.6073 Danish crowns) (Reporting by Terje Solsvik in Oslo and Nikolaj Skydsgaard in Copenhagen; Editing by Tom Hogue, Devika Syamnath and Pravin Char)