Moody's Investors Service said it has affirmed K-Sea Transportation Partners LP's non-investment grade debt ratings, which were under review for possible downgrade after a $205 million acquisition, according to a report on http://money.cnn.com. K-Sea shares jumped $2.10, or 5.9 percent, to $37.58 in afternoon trading. The stock has traded between $33.90 and $48.50 during the past 52 weeks. The ratings service began its review of the oil tank barge operator's ratings on June 27, after the company announced it had agreed to acquire transportation operators Smith Maritime Ltd. and Sirius Maritime LLC for $205 million.