* Retail sales unexpectedly fall in June
* Glaxo to buy Human Genome after sweetened $3 billion offer
* Visa at all-time high, Mastercard rises on lawsuit settlement
* Indexes down: Dow 0.2 pct, S&P 0.1 pct, Nasdaq 0.3 pct
By Edward Krudy
NEW YORK, July 16 (Reuters) - A surprise decline in June retail sales was the latest worrying sign from the economy, pushing stocks slightly lower on Monday, but Citigroup earnings limited losses in another forecast-beating report from a bank.
The S&P 500 has fallen in seven of the last eight sessions, weighed down by concerns about the economy. Still, in a sign of resilience, the index is up roughly 7 percent from a low hit early in June despite the worsening economic data.
The drop in retail sales in June, the third consecutive monthly decrease, contrasted with economists' expectations for a small increase and was the latest sign the recovery is flagging, a major concern for investors.
Shares of Citigroup gained around 1 percent after the third largest U.S. bank reported profit that came in above analysts' estimates. That was despite a 12 percent drop in quarterly earnings due to losses from credit crisis-era assets.
Giri Cherukuri, head trader at OakBrook Investments, which oversees $1.3 billion in Lisle, Illinois, said there was a battle between better-than-expected earnings in the financial sector and worries about the economy.
"The next week or so the market will be driven more by earnings than economic numbers," he said, noting that recent cautious outlooks from U.S. corporations could translate into disappointing earnings as reporting season unfolds.
Citigroup earnings follow results from JP Morgan Chase on Friday that sparked a rally and broke a six-day streak of losses by the Dow industrials.
The Dow Jones industrial average dropped 28.65 points, or 0.22 percent, to 12,748.44. The Standard & Poor's 500 Index fell 1.63 points, or 0.12 percent, to 1,355.15. The Nasdaq Composite Index dropped 7.42 points, or 0.26 percent, to 2,901.05.
"Three months in a row of lower retail sales is pretty concerning. People are going to have to lower their GDP estimates," said Paul Zemsky, head of asset allocation at ING Investment Management in New York. "Given that, I'm surprised the market is holding so well."
Zemsky said expectations that earnings turn out better than feared could be one reason. Record low U.S. Treasury bond yields and expectations that the Federal Reserve could support the economy have also helped prop up stocks.
The World Trade Organization ruled in favor of the United States, finding that China discriminates against foreign bank cards. The decision could help U.S. credit card companies like Visa, Mastercard and American Express.
In another credit card development, Visa Inc and MasterCard Inc and banks reached a $7.25 billion settlement with U.S. retailers in a lawsuit late on Friday.
Visa rose 2.4 percent to $127.08 and MasterCard shares gained 1.8 percent to $437.43. American Express shares rose 1.5 percent to $58.79.
In mergers and acquisitions news, GlaxoSmithKline is to acquire its long-time partner Human Genome Sciences Inc for $3 billion, ending a three-month hostile pursuit of the U.S. biotech company on friendly terms after sweetening its offer. Shares of Human Genome rose 4.6 percent to $14.20.
In another healthcare deal, private equity firm TPG said it would buy U.S.-based Par Pharmaceutical for $1.9 billion, sending Par shares up 36.7 percent to $50.