Merck still sees investment grade ratings after Sigma-Aldrich deal

FRANKFURT (Reuters) - Drugs and chemicals maker Merck KGaA expects its credit ratings to remain at investment grade levels following its planned acquisition of Sigma-Aldrich , its finance chief said. "We will face a downgrade by the credit rating agencies, however this downgrade will be moderate," Merck Chief Financial Officer Marcus Kuhnert said during a conference call on Monday. "We will absolutely maintain our solid investment grade rating," he said. Drugs and chemicals maker Merck earlier on Monday said it agreed to acquire Sigma-Aldrich for $17 billion in cash to boost its Merck Millipore lab supplies business in the biggest takeover in the German group's history. (Reporting by Ludwig Burger; Writing by Maria Sheahan; Editing by Arno Schuetze)