WARSAW, JAN. 13 -- West German Foreign Minister Hans-Dietrich Genscher said here today that Polish-West German relations could achieve a "breakthrough" this year after a long freeze, but offered no new financial aid to a Polish government starved for western credits.

Ending a four-day visit, his first official stay in Poland since the imposition of martial law in 1981, Genscher said he hoped a visit to Poland by West German Chancellor Helmut Kohl could be arranged by the end of the year, marking a turning point in political ties.

Genscher also said that Bonn looks "with interest and sympathy" on efforts by the government of Gen. Wojciech Jaruzelski to reorganize the economy and liberalize political life.

However, Genscher offered no firm commitment by Bonn to the new credits that have become a key goal for Poland in dealings with western nations. Staggering under a $36 billion foreign debt and unable to win significant new loans since 1981, Warsaw maintains it cannot stabilize the economy without renewed western assistance.

Diplomats here said that the visit, while failing to produce a breakthrough on financial or other bilateral issues, had consolidated an improved atmosphere between Bonn and Warsaw and further strengthened the diplomatic position of Jaruzelski's government, which suffered through years of isolation and economic boycott after suppressing the Solidarity trade union.

Polish-West German relations are troubled by issues such as Bonn's concern about treatment of a German ethnic minority in Poland -- which Poland insists does not exist -- and Polish fears about alleged West German designs on former eastern territories ceded to Poland after World War II.

Genscher won praise from Polish officials and the state-run press by once again renouncing German claims on old territories and affirming support for a 1970 treaty in which Bonn recognized Poland's postwar borders.

Genscher said Polish Foreign Minister Marian Orzechowski would visit Bonn in the first half of this year and indicated that the visit would be intended to consolidate new agreements for Kohl's prospective trip here. He added that Jaruzelski had also suggested a possible visit to Poland by President Richard von Weizsaecker, which would be the first by a West German head of state.

In a gesture of continued support, Genscher met yesterday with Solidarity leader Lech Walesa and visited the grave of pro-Solidarity priest Jerzy Popieluszko. Popieluszko's assassination by security forces in October 1984 contributed to the cancellation of Genscher's last planned visit to Poland, scheduled for the following month.