By Jan Strupczewski and Anna Ringstrom

STOCKHOLM (Reuters) - A spying scandal at Sweden's flagship telecoms company Ericsson widened Friday as the firm suspended two more employees who it believes may have contributed to leaking company secrets to a foreign intelligence service.

A senior Ericsson source said Russia was the foreign power involved.

Loss-making Telefon AB LM Ericsson is the world's biggest producer of mobile phone networks and is also involved in developing radar and missile guiding systems for the high-tech JAS 39 Gripen fighter plane, Sweden's main strike warplane.

The suspension of the two, whom Ericsson identified only as working in development units, follows Wednesday's detention by the police of two employees, also from development units, and one former employee on suspicion of industrial espionage.

"At this time the two are not suspected of any crime, but they could have broken Ericsson's internal security or secrecy rules," the company said in a statement.

The main suspect, the former employee, was taken into custody as he was meeting a foreign intelligence officer.

A Russian diplomat is likely to be expelled from Sweden as a result, an intelligence source said, but a Foreign Ministry spokeswoman said Friday no one had been expelled so far.

Ericsson spokesman Henry Stenson said the involvement of the two people suspended Friday had been discovered Wednesday, but Ericsson waited until Friday before taking action to underline their different status in the case.

"They are not suspected of espionage ... (but) we have reason to believe they may have handed over information to the main suspect," Stenson told a news conference.

"If our suspicions turn out to be correct, in all likelihood there will be grounds for them to be sacked."

NOT MILITARY SECRETS

A prosecutor was asking Stockholm district court later on Friday for the first three Swedes caught Wednesday to be detained until police complete investigations, because they might escape.

Prosecutor Tomas Lindstrand said in a court application, a copy of which was obtained by Reuters, that the three were suspected of serious espionage or serious industrial espionage.

Ericsson would not say what documents had been leaked, but a senior company source said they did not appear to have been linked to any military projects.

Sweden's Justice Ministry declined to comment Friday. No one was available for comment at the Russian embassy or in Moscow because of a public holiday in Russia.

Ericsson has recently laid off staff as part of a cost-cutting package designed to put it back in the black some time in 2003.

Stenson reiterated Friday that to the company's best knowledge the leaking of the documents had caused limited damage, even though it had been going on for some time.

The Ericsson affair is the biggest industrial espionage case in Sweden since a Swedish worker of Swiss-Swedish engineering group ABB was detained in Feburary, 2001, on suspicion of spying for Russia.

The man was released after two days for lack of evidence and given back his old job at ABB Power Systems.