* Staples (NasdaqGS: SPLS – news) , Office Depot (NasdaqGS: ODP – news) in advanced merger talks – WSJ

* Aetna (NYSE: AET – news) posts Q4 results, raises 2015 outlook

* Futures up: Dow 40 pts, S&P 4.25 pts, Nasdaq 5.25 pts (Adds oil gains, updates prices)

By Chuck Mikolajczak

NEW YORK, Feb 3 (Reuters) – Dow 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 (Berlin: DI6.BE – news) of offshore contract driller Transocean (NYSE: RIG – news) gained 4.2 percent to $ 18 in premarket trading.

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 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 (Shanghai: 600875.SS – news) . 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 (HKSE: 3366.HK – news) . 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 (Xetra: A1J5UR – news) 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 (NasdaqGS: ADVS – news) agreed to be acquired by SS&C Technologies (NasdaqGS: SSNC – news) 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)