LOS ANGELES — The chief financial officer of Donald Sterling's properties said Monday that the billionaire may be forced to sell a large portion of his real estate empire to cover $500 million in loans if he persists in refusing to sell the Los Angeles Clippers for $2 billion. Darren Schield, who oversees the finances of The Sterling Family Trust, testified Monday that three banks are ready to recall their loans to Sterling because of his decision to dissolve the trust. His move was designed to rescind his signed agreement for the sale of the Clippers, a team he bought for $12 million.