The urban guerrilla group Red Army Faction claimed responsibility for Tuesday's shotgun attack on a leading West German government employee, according to a letter received by news organizations on Wednesday.

In the letter dated September 20 the group said: "Today we, with the commando Khaled Aker, have attacked the state secretary at the Finance Ministry Hans Tietmeyer."The letter was signed Kommando Khaled Aker, Red Army Faction, and bore the sign of the group.

Tietmeyer, one of the organizers of this week's International Monetary Fund (IMF) and World Bank meeting in West Berlin, escaped injury in the attack, in which his car was hit in about 10 places as he was being driven to work.

Security sources in Bonn said they believed the Red Army Faction's claim of responsibility was genuine.

The six-page typed document accused Tietmeyer of being responsible for "genocide and mass misery in the Third World."

"As a delegate of the IMF and World Bank . . . he develops and forces through the imperialist policy of annihilation through hunger and counter-insurgency against the peoples of dependent countries in the south," it added.

The Red Army Faction killed several prominent government and industrial figures in its heyday in the 1970s and early 1980s. It last struck in October 1986 when a senior Foreign Ministry aide was shot dead in a Bonn street.

The claim said Tietmeyer, 57, was "the strategist and one of the leading players in international crisis management."

It was accompanied by statements in Italian and German with the emblems of the RAF and the Red Brigades, an Italian guerrilla group known to have had links to the RAF.

These statements, dated September 1988, made a general condemnation of Western economic and financial policies, and spoke of a unified attack on "imperialist power."

It ended with the slogan: "Build up the unity of the forces of struggling revolutionaries in attack. Organize the front. Fight together."