Without a netting agreement, the credit exposure is the sum of the positive market values (since negative values represent a liability to the firm, not an exposure): Credit exposure without netting = $\max(120,0) + \max(85,0) + \max(-65,0) + \max(-50,0) + \max(80,0) + \max(-90,0) + \max(75,0) + \max(10,0) + \max(-140,0)$ $= 120 + 85 + 0 + 0 + 80 + 0 + 75 + 10 + 0 = 370$

With a netting agreement, the credit exposure is the maximum of the sum of all market values and zero: Credit exposure with netting = $\max(120 + 85 - 65 - 50 + 80 - 90 + 75 + 10 - 140, 0)$ $= \max(370 - 345, 0) = \max(25, 0) = 25$

The improvement in credit exposure is the difference between the exposure without netting and the exposure with netting: Improvement = $370 - 25 = 345$.