A bill to declare a moratorium on Mitchell-Lama buyouts cleared an important hurdle in Albany last night, but sponsors still face an uphill battle to secure passage. The bill, originally introduced in the Senate by Sens. Liz Kruger (D-Upper East Side) and Tom Duane (D-Chelsea), will be introduced in the Assembly this week by Assembly members Vito Lopez (D-Brooklyn) and Linda Rosenthal (D-Upper West Side). While the support of Lopez makes Assembly passage more likely, Kruger and Duane have a mountain to climb in the Senate. Sources in the Senate Republican Conference have declared the bill dead. By John Celock