A Russian military transporter plane flew about 4.5 kilometers (3 miles) into Finnish airspace along the southern coast for three minutes on Sept. 14, prompting Finland to demand an explanation from Moscow.
"According to Russia's investigation, the violation of airspace was not intentional; it was caused by inadequate exchange of information between the flight crew and ground stations," the ministry said.
"Russia regretted the incident and proposed that specialist discussions be held so that corresponding situations could be avoided in future."
Russian Ambassador Alexander Rumyantsev told Finnish Foreign Minister Ilkka Kanerva that Russia had "investigated the alleged violation of airspace on the basis, among others, of material supplied by Finland," a ministry statement said. "Russia admits having violated Finnish airspace."
Kanerva said he was satisfied with the explanation, and welcomed Moscow's proposal for talks.
Similar violations were observed in August 2005 and April 2006, officials said. Last year, Russia apologized for violating Finnish airspace, following about a dozen such incidents over a period of two years and a protest from Finland.
International airspace along the southern Finnish coast is narrow, and military observers said they had expected such violations.
Russian planes, mostly military transporters, frequently fly between the Baltic port enclave of Kaliningrad and bases near the city of St. Petersburg.