(Corrects to add dropped word "is" in first paragraph)
* IMF says will help Greece if asked to
* ECB's governing council to hold call this afternoon
* Aetna falls after Humana deal, other insurers lower
* Energy index leads losses as oil prices fall
* Indexes down: Dow 0.22 pct, S&P 0.21 pct, Nasdaq 0.14 pct
By Tanya Agrawal
July 6 (Reuters) - U.S. stocks erased most of their earlier losses, even turning positive briefly, on Monday after the International Monetary Fund said it is ready to assist Greece if asked.
Greeks rejected the conditions of a rescue package from creditors on Sunday, but investors remained optimistic that a deal could be reached to prevent the country's exit from the euro zone.
Stock markets globally fell, but analysts said the declines were less than expected due to expectations that the European Central Bank would act to limit any damage.
"The referendum doesn't really change anything with the negotiations," said Mark Luschini, chief investment strategist at Janney Montgomery Scott in Philadelphia.
"I think after the initial knee jerk reaction, the majority opinion is that there is still a possibility of some sort of a deal that keeps Greece in the euro zone."
The ECB's governing council is due to hold a conference call on Monday afternoon to discuss the provisions of emergency funding to Greece's banks. A new deal is needed for Greece to meet a July 20 deadline to repay $3.9 billion of bonds to the ECB.
Greece's finance minister quit after the vote and Prime Minister Alexis Tsipras said his government was ready to return immediately to negotiations with creditors.
U.S. stocks opened more than half a percent lower, but by 11:39 a.m. ET they had pared most of their losses and even briefly turned positive after the IMF offered a helping hand.
The Dow Jones industrial average was down 46.73 points, or 0.26 percent, at 17,683.38. The S&P 500 was lower 5.71 points, or 0.27 percent, at 2,071.07. The Nasdaq Composite was down 15.25 points, or 0.3 percent, at 4,993.97.
Nine of the 10 major S&P 500 sectors were lower. The energy index led the declines with a 0.85 percent fall as oil prices fell more than 3 percent after the Greek referendum and on a strengthening dollar. Chevron fell as much as 1.5 percent to $94.68, its lowest since November 2011.
U.S. economic growth prospects got a boost after Institute for Supply Management data showed the pace of growth in the U.S. services ticked higher in June after dropping in May.
The Federal Reserve has said it will raise rates only when it sees a sustained economic recovery.
Health insurer Humana's shares rose 3.6 percent to $194.50 after bigger rival Aetna said on Friday it would buy the company for about $37 billion. Aetna fell 4.9 percent at $119.20.
The deal follows weeks of intense discussions about potential combinations among health insurers, but rigorous scrutiny from U.S. regulators could also make mergers more difficult. Anthem and Cigna, which are in takeover talks, declined more than 1 percent.
Weight Watchers soared 16.4 percent to $4.76 after the New York Post reported an activist hedge fund was in talks with potential partners to buy the company. The hedge fund and a partner "would like to offer perhaps double" Thursday's closing price, the report said.
Declining issues outnumbered advancers on the NYSE by 1,912 to 1,038. On the Nasdaq, 1,680 issues fell and 976 advanced.
The S&P 500 index showed five new 52-week highs and 28 new lows, while the Nasdaq recorded 23 new highs and 106 new lows. (Editing by Savio D'Souza)