A big name on Wall Street is taking aim at some of its neighbors best business. Lehman Brothers is boosting its prime brokerage unit in a challenge to the industry's dominant pair, Goldman Sachs and Morgan Stanley. According to Financial News, David Goldfarb, Lehman's chief administrative officer, told a CIBC World Markets analyst that its current prime brokerage operation is too small. Roughly half the size of its two biggest competitors, states a Lehman research note, pointing to giants of the field. The analyst, Meredith Whitney, wrote in a research note, The growth of the prime brokerage business remains a high priority and big push for the firm. She noted that the company has the best performing stock of all brokerages, soaring 47% in share price last year. For the past decade, Lehman has had the fastest compound annual earnings growth rate of its large cap bank peers and has grown four times as fast as the S&P during the same period, Whitney said in the report, adding that she expects LehmanÕs earnings to increase by more than 20% this year.