OSLO, July 16 (Reuters) - Norwegian fertiliser company Yara on Friday proposed an additional dividend of 20 Norwegian crowns ($2.27) per share to be paid in the third quarter after strong second-quarter cash flow.

April-June earnings before interest, tax, depreciation and amortisation (EBITDA), excluding non-recurring items, rose to $775 million from $588 million and topped the $769 million expected by 10 analysts, Refinitiv Eikon data showed.

Higher prices more than offset rising costs of natural gas used to make nitrogen fertilisers, the Oslo-listed firm said.

"Nitrogen fertiliser markets are robust, with significantly higher prices than a year ago reflecting both stronger demand and limited new supply," Yara said.

European natural gas prices have continued to rise from record low levels in 2020 but have been more than offset by higher nitrogen prices, the company said.

Yara said it expected to pay $380 million more for natural gas in the third quarter than a year earlier, and $300 million more in the fourth quarter.

($1 = 8.8176 Norwegian crowns) (Reporting by Victoria Klesty)