Sterling Bancorp has announced it would buy Astoria Financial Corp in an all-stock deal valued at about $2.2 billion to create the sixth largest regional bank in the New York City area by deposits.

Astoria's shareholders will receive 0.875 Sterling shares for each share held. The resulting offer price of $21.92 per share represents a premium of 18.6 percent to Astoria's Monday closing price.

Astoria's shares were up 11.8 percent at $20.67 in morning trading, while Sterling's stock was down 3.4 percent at $24.20.

The deal follows a spree of mergers between regional U.S. banks last year, which were spurred by low interest rates, lagging returns on equity and tough regulations.

However, U.S. President Donald Trump has promised simpler regulations and last month ordered reviews of major banking regulations put in place following the 2008 financial crisis.