GlaxoSmithKline, the British drug giant, has agreed to pay $750 million to settle criminal and civil complaints that the company for years knowingly sold contaminated baby ointment and an ineffective antidepressant the latest in a growing number of whistle-blower lawsuits that drug makers have settled with multimillion-dollar fines. Altogether, GlaxoSmithKline sold 20 drugs with questionable safety that were made at a huge plant in Puerto Rico that for years was rife with contamination. Cheryl D. Eckard, the company's quality manager, asserted in her whistle-blower suit that she had warned Glaxo of the problems but the company fired her instead of addressing them. Among the drugs affected were Paxil, an antidepressant; Bactroban, an ointment; Avandia, a troubled diabetes drug; Coreg, a heart drug; and Tagamet, an acid reflux drug. Justice Department officials announced the settlement in a news conference Tuesday afternoon in Boston, saying a $150 million payment to settle criminal charges was the largest such payment ever by a manufacturer of adulterated drugs. The outcome also provides $600 million in civil penalties. The share to the whistle-blower will be $96 million, one of the highest such awards in a health care fraud case.