LONDON -(Dow Jones)- Research-based pharmaceutical and healthcare company GlaxoSmithKline PLC (GSK) said Wednesday it won't participate in Human Genome Sciences Inc (HGSI) strategic alternatives review process and will instead start a tender offer this week to buy all of the outstanding shares of HGS for $13.00 per share in cash. MAIN FACTS: -GSK's offer represents a premium of 81% to HGS's closing share price of $7.17 on April 18. -GSK values the long relationship it has with HGS and has clearly stated its preference to complete a transaction on a friendly basis in a timely fashion. -GSK remains willing to meet and review its offer with HGS at any time. -GSK shares closed Tuesday at 1407 pence valuing the company at GBP71.83 billion. -By Ian Walker, Dow Jones Newswires; 44-20-7842-9296; ian.walker@dowjones.com