The board that regulates rents for more than one million rent-stabilized apartments in New York City voted on Monday night for a freeze on one-year leases, an unprecedented move in its 46-year history.

The 7-to-2 vote by the city’s Rent Guidelines Board was an acknowledgment of the precarious situation of many tenants whose incomes have not kept pace with housing costs. It also was the first decision on rent levels by a nine-member board appointed in its entirety by Mayor Bill de Blasio.

The board, one of the few tools the mayor has to directly influence the cost of housing in the city, also voted to increase rents on two-year leases by 2 percent, a historic low.

The mayor refrained from publicly calling for a rent freeze as he had done last year. But his housing plan aims at building new affordable housing while staving off the loss of existing affordable units — either through rent increases or the removal of stabilized apartments from regulation.