The Syrian Observatory for Human Rights said 30 regime soldiers and 39 rebel fighters had been killed in battles around Al-Maleh, north of Aleppo, since Wednesday afternoon.
Jihadists fighting for the Al-Nusra Front, the Syrian branch of Al-Qaeda, were also killed, said Observatory head Rami Abdel Rahman, who did not provide a precise number.
The government of President Bashar al-Assad has been attempting to seize Al-Maleh for more than two years.
His forces have been trying for months to surround Aleppo by cutting supply lines between rebel-held districts of the city and nearby Turkey, which supports opposition forces.
For nearly a week, regime troops backed by Syrian and Russian warplanes have been battling for control of Al-Maleh.
Assad’s regime is also attempting to cut the Castello Road, a key supply route from the Turkish border to rebel-held eastern suburbs of Aleppo.
The pro-regime website Al-Masdar News reported that the Syrian army withdrew from the farms of Al-Maleh as they faced a rebel counter-offensive led by the Al-Nusra Front.
It said rebels attacked government forces with two suicide car bombs.
The Observatory said two children were killed by regime bombs in a rebel-held area of Aleppo.
The majority of Aleppo province is controlled by Al-Nusra and its Islamist allies, while the city, the country’s pre-war commercial capital, has been divided since July 2012 into rebel-held and regime-held areas.
Thirteen civilians including four children were also killed in regime missile attacks on Eastern Ghouta in the Damascus region, the Observatory reported Thursday, updating an earlier toll.
The conflict in Syria, which has lasted five years, has killed more than 280,000 people.