A federal judge has released a real estate hold on the Quincy home of Catherine Greig, the girlfriend of gangster James “Whitey” Bulger, so that she can pay a $150,000 fine. Lawyers for Greig, 61, told US District Court Judge Douglas P. Woodlock that she has signed a purchase and sales agreement for the home, last valued at $343,700. Greig will use the proceeds from the sale to pay the $150,000 fine, which was part of her sentence for helping Bulger remain on the lam for 16 years. She is also serving an eight-year prison sentence.Milton Valencia can be reached at email@example.com. Follow him on Twitter @MiltonValencia.