Ex-Merrill Lynch boss John Thain — pilloried for his $1.2 million office renovation as head of the giant brokerage firm — is backing an austerity plan at his new company, commercial lender CIT Group.

CIT said yesterday it won’t pay employee bonuses for 2009, a year marred by the firm’s bankruptcy.

The decision “is the appropriate course of action given CIT’s financial performance last year,” according to a statement e-mailed by company spokesman Curt Ritter.

The New York-based company expects to report a loss of $4 billion for 2009, before accounting gains from the bankruptcy court’s cancellation of debt, CIT said in a regulatory filing this week.