S&P 500 index extended gains on Thursday as Greece claimed it had concluded debt agreement and US jobless claims fell more than expected last week. US benchmark added 0.15% or 1.99 points and closed at 1,351.95, led by technology stocks. Akamai Technologies rallied 10.5% and Visa Inc. surged 3.8% after their earnings beat analyst projections. Apple Inc. jumped 3.5% after the company announced it will release its next-generation iPad tablet in March.