While many West European capitals speculate over the ''Bulgarian connection'' in the 1981 shooting of Pope John Paul II, Turkey is discreetly silent. Publicly, officials don't talk about the case, not even the reported ''confessions'' of would-be Turkish assassin, Mehmet Ali Agca.
Privately, these officials explain that they do not consider in Turkey's interests any public statement on an ongoing judicial case and investigation. They are also somewhat skeptical of Italian allegations that take for granted Bulgaria's role in using Mr. Agca in a KGB-planned plot against the Polish Pope.
But at least part of this skittishness is attributable to Turkey's reluctance to upset the Bulgarians, analysts here say. These analysts see three main reasons for this:
* Bulgaria is a major transit road for hundreds of thousands of Turks - mainly workers - and Turkish goods traveling to and from Europe. Closing of that passage would be very damaging to Turkey's economy.
* Bulgaria provides electrical power to western Turkey, and the two neighboring countries have close trade and economic ties, which work to Turkey's advantage.
* Bulgaria is a loyal ally of the Soviet Union, and any deterioration of Turkish-Bulgarian relations could adversely affect Turkey's ties with Moscow.
Despite these ties, however, Turkey is taking a keen interest in alleged Bulgarian complicity in illicit activities carried out in Turkey, such as arms smuggling. Bulgaria can hardly be pleased with this turn of events.
For one thing, Turkey has requested the extradition of Bekir Celenk, a wealthy Turk who is considered one of the godfathers of the Turkish Mafia, operating in Sofia, the Bulgarian capital. Mr. Celenk was detained last month by the Bulgarian authorities following allegations that he was the main contact man with Agca in the plot against the Pope. And he has been charged by Turkish authorities with large-scale smuggling, including arms and foreign currency.
Last week, Bulgaria announced it would set Celenk free within a month unless Ilario Martella, the Italian magistrate investigating the papal shooting, comes to Sofia for an investigation.
Turkey is expected to repeat its demand for extradition, particularly in view of Sofia's intention to release Mr. Celenk. The Turks consider him a key person not only in the alleged plot against the Pope, but also in various ''dirty affairs'' conducted in Sofia and Turkey in recent years.
The Turks say they have plenty of evidence on the Turkish Mafia's activities in Bulgaria, particularly in the smuggling of arms that ended up in the hands of Turkish terrorist organizations before the Turkish coup of 1980.
In a book published in 1980 a noted Turkish investigative journalist, Ugur Mumcu, disclosed details on such smuggling operations. These allegations were later confirmed by authorities. Both Mr. Mumcu and Turkish intelligence officials have stated clearly that it was inconceivable that Bulgarian authorities were unaware of such activities.
They have, in fact, expressed strongly their belief that the Buglarians were actively supporting such operations. Many Turks also feel that all this was part of a plan in the late 1970s to destabilize Turkey through political violence.
Meanwhile, Turkish military and judicial authorities announced last week they are reinvestigating the case of Abdi Ipekci, the Turkish editor who was murdered by Agca in 1979. It is believed now that Agca had more accomplices than previously proved by the Turkish investigators. New evidence here is likely to shed light on the papal shooting.