Wall Street to gain at open on Greek deal hopes, oil lift

NEW YORK (Reuters) - U.S. stock index futures pointed to a modestly higher open on Tuesday, with the benchmark S&P 500 index set to continue a rally fueled by hopes of a deal on Greek debt and by firmer oil prices.

Stocks rallied late in the prior session on signs Greece was softening its approach to debt negotiations. A source told Reuters that Greek Finance Minister Yanis Varoufakis, in London to reassure private investors he was not seeking a showdown with Brussels over a new debt agreement, said the new left-wing government would spare privately held bonds from losses.

Adding support was a further gain in oil prices, with U.S. crude up 2.4 percent to $50.76 and Brent up 2.7 percent to $56.21. The advance came after BP said it would cut capital expenditure, raising expectations a supply glut will be lessened. Shares of offshore contract driller Transocean gained 4.2 percent to $18 in premarket trading. [O/R]

S&P 500 e-mini futures were up 4.25 points and fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract, indicated a higher open. Dow Jones industrial average e-mini futures <1YMc1> rose 40 points and Nasdaq 100 e-mini futures added 5.25 points.

The S&P 500 is still down more than 3 percent from its Dec. 29 record high amid lackluster corporate earnings and data showing the U.S. economy growing at a slower pace than investors anticipated. January's 3.1 percent decline was the worst monthly performance for the index in a year.

According to Thomson Reuters data through Monday morning, of 226 companies in the S&P 500 to report results, 73 percent beat expectations. The expected growth rate for the quarter sits at 5.4 percent, down from 11.2 percent expected on Oct. 1.

Aetna , the third-largest U.S. health insurer, reported fourth-quarter earnings that matched Wall Street expectations and raised its 2015 forecast for operating earnings.

Stratasys shares plunged 26.2 percent to $59.10 in premarket after the company cut its 2014 adjusted profit estimates for a second time.

Office Depot shares surged 13 percent to $8.62 before the opening bell after the Wall Street Journal reported the company is in advanced talks to merge with Staples Inc . Staples shares jumped 13.1 percent to $19.38.

In other merger news, Advent Software agreed to be acquired by SS&C Technologies for $2.7 billion in cash, sending shares up 5.6 percent to $43.70.

Economic data expected Tuesday includes December factory orders at 10:00 a.m. (1500 GMT) and U.S. vehicle sales throughout the day.

(Editing by Bernadette Baum)