A series of bombs exploded early today on the grounds of four U.S. military installations and two U.S. companies, causing about $150,000 in damages just nine days before President Reagan is scheduled to arrive here.

No one was injured by the bombs.

Another bomb placed at the base of an armed forces network radio transmission tower in West Berlin was defused before going off.

A leftist terrorist group known as the Revolutionary Cells claimed responsibility for the attacks against the U.S. bases in central West Germany in a letter tying the explosions to Reagan's visit. West German authorities said there was as yet no indication of who set the bombs in Duesseldorf and West Berlin.

"We are not waiting until Reagan comes," declared a statement received by the Deutsche Presse-Agentur news service and signed with a star and the letters RZ, the mark of the Revolutionary Cells. "As a start for a hopefully very loud, eventful and unforgettable reception, we have today attacked some of the nests of the U.S. military in the Federal Republic of Germany."

West Germany's public prosecutor, Kurt Rebmann, warned several weeks ago that leftist extremists might try to attack U.S. facilities or military officials in Germany before Reagan's arrival and a meeting June 10 in Bonn of leaders of the North Atlantic Treaty Organization.

The NATO conference is being held here at the urging of the Bonn government, which hopes to use the occasion to underline West Germany's loyalty to the Atlantic Alliance and squelch reports of anti-Americanism here.

Major street demonstrations, though, planned for Bonn and Berlin to coincide with the summit have taken on a decidedly anti-U.S. tone. More than a year of protest activities against U.S. military and foreign policies has served as a springboard for leftist violence.

Police and U.S. military officials put the times of the explosions between 12:30 and 3 a.m. today. A bomb placed under an air conditioning unit outside the large headquarters building of the U.S. 5th Army Corps in Frankfurt blew out more than 40 windows in the U-shaped structure up to its fifth floor.

Three other bombs went off outside officer clubs at military bases in Hanau, Gelnhausen and Bamberg, shattering windows and, in Gelnhausen, seriously damaging the club's deserted interior.

In Duesseldorf, explosive devices planted near the entrances of the International Business Machines Corp. and Control Data Corp. did extensive damage to lobby areas, according to a city police spokesman.

The bombings were the first show of renewed terrorist activity here since a rocket-propelled grenade hit a car in Heidelberg last September carrying U.S. Army Commander Gen. Frederick Kroesen. The general was only slightly injured in the assassination attempt.

Two weeks earlier, a bomb explosion on the grounds of U.S. Air Force headquarters in Ramstein had injured 20 people.

Responsibility for both attacks was claimed by the Red Army Faction, the name adopted by members of the extremist gang once led by the late Andreas Baader and Ulrike Meinhof, who masterminded a series of killings, kidnapings and bombings in the 1970s.

Specialists on German terrorism say the Revolutionary Cells is really a patchwork of smaller successor groups to the Red Army Faction.