* ECB President Draghi announces bond-buying program
* Verizon, F5 Networks both lower after results
* Royal Bank of Canada to buy City National
* Futures up: Dow 52 pts, S&P 6.75 pts, Nasdaq 9.75 pts (Updates with data, ECB move)
By Ryan Vlastelica
NEW YORK, Jan 22 (Reuters) - U.S. stock index futures pointed to modest gains at the open on Thursday after the European Central Bank announced expanded measures to stimulate the region's economy.
The ECB will buy 60 billion euros worth of assets per month, the central bank's President Mario Draghi said, in a program that will last through September 2016.
The money will include some from existing programs. Countries under a bailout plan, such as Greece, will be included, but with some additional criteria.
Stock index futures were volatile as Draghi spoke, fluctuating between heavy gains and levels below where they traded prior to the announcement.
"When you have every central bank in the world trying to stimulate the global economy, that's a tough thing for asset prices to fight against," said Wayne Kaufman, chief market analyst at Phoenix Financial Services in New York.
The ECB plan comes amid signs of weaker regional growth.
U.S. jobless claims fell from a seven-month high in the latest week, though the decline was less than expected.
Verizon Communications fell 0.5 percent to $48 in premarket trading after swinging to a net loss in its latest quarter, while revenue rose 6.8 percent. Travelers Cos Inc rose 1.1 percent to $106.15 after reporting a rise in net profit.
American Express Co late Wednesday reported revenue growth of 6.6 percent, though the credit card company also said it would cut more than 4,000 jobs this year as expenses and provisions for bad loans rose. Shares fell 2 percent to $85.90 in premarket trading.
F5 Networks Inc slumped 14 percent to $108.20 in premarket trading after the network equipment maker reported revenue that missed expectations for the first time in eight quarters. It also forecast current-quarter revenue and profit below market estimates.
With 11 percent of S&P 500 components having reported, about 79 percent have topped earnings expectations while 55.4 percent have beaten on revenue, according to Thomson Reuters data. That compares with the long-term average of 63 percent for earnings and 61 percent for revenue.
City National Corp jumped 19 percent to $88.80 in premarket trading after the Royal Bank of Canada said it would buy the company in a cash-and-stock deal valued at $5.4 billion.
EBay Inc rose 3 percent to $55 before the opening bell, a day after it said it was exploring a sale or public offering of its enterprise unit, and announced an agreement with activist investor Carl Icahn that will give investors a greater say in its PayPal payments unit once it is spun off.
U.S. crude futures fell 0.4 percent to $47.60 per barrel, erasing earlier gains of as much as 2.7 percent.
Futures snapshot at 8:54 a.m.:
* S&P 500 e-minis were up 6.75 points, or 0.33 percent, with 262,051 contracts changing hands.
* Nasdaq 100 e-minis were up 9.75 points, or 0.23 percent, in volume of 41,508 contracts.
* Dow e-minis were up 52 points, or 0.3 percent, with 32,221 contracts changing hands. (Editing by Bernadette Baum)